DBMS in Hindi BccFalna.com 097994-55505 Kuldeep Chand This EBook is basically useful if you want to learn to develop Professional Application Level Database, so that you can understand the various theoratical processes related to Database Designing like Requirement Identification, Database Normalization, Entity Relationship (ER) Diagram Creation, Data Flow Diagram (DFD), etc… This eBook is based on various kinds of Database Related Problems and then Identifying its Solutions, so that you can create a Database Schema on the basis of the requirement. Relationship of a Relation Database is the main fundamental concept and in this eBook, I have tried my best to explain Various Relationship Concepts like One-to-One, One-to- Many and Many-to-Many with easy to understand Examples. Database Normalization is another the most important concept for developing a well performing Database, so I have included it with easy to understand Detailed Examples too.
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DBMS in Hindi
B c c F a l n a . c o m 0 9 7 9 9 4 - 5 5 5 0 5
Kuldeep Chand This EBook is basically useful if you want to learn to develop Professional Application Level Database, so that you can understand the various theoratical processes related to Database Designing like Requirement Identification, Database Normalization, Entity Relationship (ER) Diagram Creation, Data Flow Diagram (DFD), etc… This eBook is based on various kinds of Database Related Problems and then Identifying its Solutions, so that you can create a Database Schema on the basis of the requirement. Relationship of a Relation Database is the main fundamental concept and in this eBook, I have tried my best to explain Various Relationship Concepts like One-to-One, One-to-Many and Many-to-Many with easy to understand Examples. Database Normalization is another the most important concept for developing a well performing Database, so I have included it with easy to understand Detailed Examples too.
Table of Contents Database Management System .................................................................... 8
Introduction ............................................................................................................ 8 Problem – Doing Something ................................................................................ 12 System – Interrelated Group of Units to Solve a Problem .................................... 13
Database Management System – DBMS ................................................... 14
Requirement of Good Database Design ............................................................... 20 Effects of Poor Database Design ......................................................................... 21
Unnecessary Duplicated Data and Data Consistency ....................................... 22 Data Insertion Problems ................................................................................... 24 Data Deletion Problems .................................................................................... 26
Meaningful Identifiers ........................................................................................... 27 Entities and Data Relationships ........................................................................... 28 Entities and Their Attributes ................................................................................. 28 Entity Identifiers ................................................................................................... 29 Single-Valued and Multi-Valued Attributes ........................................................... 31 Identifying Problem Related Entities .................................................................... 34 Documenting Logical Data Relationships ............................................................. 35 Entities and Attributes for Music Store Application ............................................... 37 Domains .............................................................................................................. 38
Basic Data Relationships ............................................................................ 42
One To One Relationships ................................................................................... 43 One To Many Relationships ................................................................................. 45 Many To Many Relationships ............................................................................... 46 Weak Entities and Mandatory Relationships ........................................................ 47 Documenting Relationships ................................................................................. 48 Dealing with Many To Many Relationships ........................................................... 52 Composite Entities ............................................................................................... 53 Relationships and Business Rules ....................................................................... 57 Data Modeling and Data Flow .............................................................................. 58
Translating an ER Diagram into Relations............................................................ 81 Normal Forms ...................................................................................................... 82
First Normal Form ............................................................................................ 84 Second Normal Form ....................................................................................... 90 Third Normal Form ........................................................................................... 93 Boyce-Codd Normal Form ................................................................................ 95 Forth Normal Form ........................................................................................... 97
Computer ij Stored lwpukvksa dks ,d Business Man lkyksa ckn Hkh T;ksa dk R;ksa izkIr dj
ldrk gS] ftlls ,d Business Man dks bUlkuh xyfr;ksa ls gksus okyh ijs”kkfu;ksa dk Hkh lkeuk
ugha djuk iMrk gSA ,slh gh vkSj Hkh cgqr lh fo”ks’krkvksa ds dkj.k gh vkt gj Business Man pkgs og NksVk Business dj jgk gks ;k cMk] Computer ij gh vius Business ls lEcaf/kr
lwpukvksa dks Manage djrk gSA
gj Business Man Computer ij vius Business ls lEcaf/kr t:jh Data dks Maintain djrk gS] rkfd og vius Business ls lEcaf/kr tkudkfj;ksa dks vPNh rjg ls o rsth ls izkIr dj
lds o vius Business ls lEcaf/kr fu.kZ; ys ldsA
Data – Value or a Set of Values
vfl) rF; (Facts) vad (Figures) o lkaf[;dh (Statics) dk og lewg ftl ij izfØ;k
(Processing) djus ij ,d vFkZiw.kZ (Meaningful) lwpuk (Information) izkIr (Generate) gks] Data dgykrk gSA Data eku ;k ekuksa dk ,d lewg (Value or a Set of Values) gksrk gS] ftlds vk/kkj ij (After Processing) ge fu.kZ; (Decision) ysrs gSaA
vaxzsth Hkk’kk esa Small o Capital Letters ds dqy 52 Characters gh gksrs gSa] ysfdu ;fn bUgsa
,d lqO;ofLFkr Øe esa j[kk tk,] rks gtkjksa iqLrdsa cu ldrh gSaA blfy, ;s Characters Data gSaA
Computer esa ge bUgha nks :iksa esa okLrfod thou dh fofHkUu ckrksa dks Store djrs gSa vkSj mu
ij Processing djds vko”;drkuqlkj Information Generate djrs gSaA tSls fdlh School ds fofHkUu Students dh ;s tkudkjh j[kuh gks fd fdlh Class esa dkSu&dkSu ls Students gSa] mudk Serial Number D;k gS vkSj os fdl Address ij jgrs gSa] rks ;s lHkh rF; vfl) :i esa
Computer ds fy, Data gSa D;ksafd fdlh Student ds Serial Number dks 0 ls 9 ds dqN
vadksa ds lewg ds :i esa Express fd;k tkrk gS vkSj Student dk uke o irk Characters ds
,d lqO;ofLFkr lewg ds :i esa Express fd;k tkrk gSA
tc 0 ls 9 rd ds dqN vadksa dks ,d lewg esa O;ofLFkr fd;k tkrk gS rc fdlh ,d Student dk ,d Serial Number cu tkrk gS vkSj tc fofHkUu Characters dks ,d lewg esa O;ofLFkr
fd;k tkrk gS] rc fdlh Student dk uke o Address cu tkrk gSA ;s uke o Address gh fdlh Student dh dqN Information iznku djrs gSaA
gksrs gSa] rks mu bdkbZ;ksa ds lewg dks System dgk tkrk gSA
tSls dksbZ Hospital ,d System gksrk gS ftls Hospital System dgk tkrk gSA Doctors, Nurses, fpfdRlk ls lEcaf/kr fofHkUu midj.k] Operation Theater, Patient vkfn fdlh
Hospital System dh fofHkUu bdkbZ;ka gSaA ;fn bu esa ls fdlh dh Hkh deh gks rks Hospital v/kwjk gksrk gSA blh rjg ls Computer Hkh ,d System gS] ftlds fofHkUu vo;o tSls fd
Monitor, Mouse, Keyboard, CPU o leL;k dk lek/kku izkIr djus ls lEcaf/kr Application Software vkfn gksrs gSa vkSj ;s lHkh vkil esa feydj fdlh leL;k dk ,d mfpr lek/kku iznku
DBMS – The Fundamentals Computer esa fofHkUu izdkj ds Data dks Store o Manage djus ds fy, dqN Standard rjhdksa
dks mi;ksx esa yk;k tkrk gS] rkfd Computer }kjk fdlh Hkh le; Accurate o Up-To-Date Information dks izkIr fd;k tk ldsA ftu Standard rjhdksa dks mi;ksx esa ysdj fdlh leL;k
ls lEcaf/kr Data dks Manage fd;k tkrk gS] mu rjhdksa ds lewg dks gh Database Management System dgk tkrk gSA
fdlh ,d lewg ls lEcaf/kr lwpukvksa dks de ls de txg esa Store djus o Manipulate djus
dk lcls vPNk rjhdk ;gh gksrk gS fd ml “Group Of Information” dks ,d lkj.kh ds :i esa
Define fd;k tk,A ,d lkj.kh fdlh ,d Group ls lEcaf/kr lwpukvksa dks de ls de txg esa o
Sr_No Name Age Sex Class 123 Amit Sharma 15 Male 10 234 Rahul Varma 16 Male 10 121 Salini Bohra 15 Female 9 544 Silpa Roy 14 Female 8 534 Prince Mishra 13 Male 6 532 Devendra Bhati 14 Male 9
;fn ge bl lkj.kh esa Represent fd, x, lHkh Data dks ,d lkFk ,d Group ds :i esa ns[ksa]
rks ge dg ldrs gSa fd ftl Student dk Serial Number 123 gS] mldk uke Amit Sharma gS vkSj mldh mez 15 lky gSA lkFk gh og Class 10th esa i<rk gSA
blh rjg ls ge bl lkj.kh esa Represent fd, x, vU; Students dh Hkh fofHkUu izdkj dh
tkudkfj;ksa dks izkIr dj ldrs gSaA Database Management System esa blh rjhds dks mi;ksx
esa fy;k tkrk gS o leL;k ls lEcaf/kr bdkbZ dh ftu tkudkfj;ksa dks Computer }kjk Manage djuk gksrk gS] mu tkudkfj;ksa dks NksVs&NksVs VqdMksa esa Divide djds] mUgsa Logical Tables esa Data ds :i esa Store dj fy;k tkrk gSA
tc ge Computer }kjk fdlh leL;k dks Solve djuk pkgrs gSa] rc lcls igys gesa ml leL;k
ls lEcaf/kr mu eq[; Entities dks Identify djuk gksrk gS] ftUgsa ge Computer ij Mange djuk pkgrs gSaA mnkgj.k ds fy, ;fn ge fdlh Student ls lEcaf/kr fofHkUu izdkj dh
School dk Principal mlds School esa i<us okys lHkh Students dh tkudkfj;ksa dks
Computer ij Maintain djuk pkgrk gS] rkfd tc Hkh mls fdlh Particular Student ls
lEcaf/kr tkudkfj;ksa dh t:jr gks] og ml Student dk Serial Number ml Student Database Application Software Input djs vkSj Computer ml Student ls lEcaf/kr lHkh
Information dks Screen ij Display dj nsA
fdlh Hkh Database System Application dks Develop djus ls igys gesa lcls igys leL;k
dks vPNh rjg ls Analyze djds ;s irk yxkuk gksrk gS fd vkf[kj ml System dh eq[;
vko”;drk D;k gS vkSj ml vko”;drk dks iwjk djus ls lEcaf/kr dqy fdrus Entities gSa o os Entities dkSu&dkSu ls gSa\ pwafd gekjh bl leL;k dks ;fn ge /;ku ls ns[ksa rks bl leL;k dh
eq[; Requirement School ds Students dh Information gh gS vkSj leL;k ls lEcaf/kr eq[;
Entity Hkh Student gh gSA
leL;k ls lEcaf/kr Entity dk irk py tkus ds ckn gesa ;s irk yxkuk gksrk gS] fd ml Entity ls lEcaf/kr fdu ckrksa dks Computer ij Maintain djuk gSA ;s ckrsa gh ml Entity dk
bl lkj.kh ds vk/kkj ij ;fn ge SrNo 001 okys Student dh tkudkjh izkIr djuk pkgsa] rks gesa
Left To Right pyrs gq, bl Serial Number okys Student dk uke Rahul izkIr gksrk gS] ftlds firk dk uke Mohan Lal gS vkSj og Falna uke dh City esa jgrk gSA bl City dk
District Pali gS vkSj og Class 10th esa i<rk gSA Rahul dh Date Of Birth 10 Feb 1982 gS vkSj mlus bl School esa 15 July 1987 dks Admission fy;k gSA ;kuh ge bl lkj.kh ds
vk/kkj ij dg ldrs gSa fd bl lkj.kh ds lHkh Fields vkil esa Logically Related gSa] blh
dkj.k ls lHkh Fields vkil esa feydj fdlh ,d Student ls lEcaf/kr lHkh tkudkfj;ka iznku
dj jgs gSaA
tc cgqr lkjs Fields tks fd vkil esa Logically Related gksa] feydj fdlh ,d Entity ls
Related fofHkUu izdkj dh tkudkfj;ka Provide djrs gSa] rks Logically Related Fields ds bl
Group dks ,d Record dgk tkrk gSA ;kuh ;fn ge fiNyh lkj.kh ds vk/kkj ij dgssa rks bl
lkj.kh dk gj Row ,d Unique Student ds Record dks Specify dj jgk gSA fdlh Record dks Database Management System dh Hkk’kk esa Tuple dgk tkrk gSA
tc fdlh leL;k esa ,d ls vf/kd Entities Involved gksrs gSa] rc mu lHkh Entities ds
vkt ftrus Hkh Businesses Database System ij fuHkZj gSa] ;kuh vius Business ls lEcaf/kr
tkudkfj;ksa dks Computer }kjk Manage djrs gSa] os lHkh Accurate o Up-To-Date Information izkIr djus ds fy, gh Computer dk mi;ksx djrs gSaA ftrus Hkh Business Corporations Computer ij vius Business ls lEcaf/kr Data dks Maintain djrs gSa] mu lHkh
dks dHkh uk dHkh fdlh uk fdlh :i esa vius Data ds Report dh t:jr gksrh gS] ftlds vk/kkj
ij ml Business dks Operate djus okyk Authorizer vius O;olk; ls lEcaf/kr t:jh fu.kZ;
ysrk gSA
blfy, ;s t:jh gks tkrk gS fd fdlh Hkh Database esa Store fd, tkus okys Data Accurate, Complete o bl rjg ls Well Organized gksus pkfg,] rkfd tc Hkh fdlh izdkj ds
Information dh t:jr gks vkSj ftl Format esa Information dh t:jr gks] ml Information ls lEcaf/kr Data dks mlh Format esa Fastly o Accurately izkIr fd;k tk ldsA
fdlh Hkh Database System dks Develop djrs le; lcls vk/kkjHkwr rF; ds :i esa blh ckr
dk /;ku j[kk tkuk gksrk gS] fd Develop fd;k tkus okyk Application pkgs Local Area Network ij Use fd;k tkuk gks ;k fdlh Web Site ls Data dks Access fd;k tkuk gks]
nksuksa gh fLFkfr;ksa esa Database ls izkIr gksus okyk Data Accurate o Fast gksuk pkfg,A ;kuh Database pkgs NksVk gks ;k cMk] ;fn ge ,d Database System dks fcuk fdlh ijs”kkuh ds
;fn Organization ftl rjhds ls dke djrk gS] ml rjhds ls Organization dks Hkfo’; esa
fdlh rjg dh ijs”kkuh dk lkeuk ugha djuk iMrk gS] rks fuf”pr :i ls ml Organization ds
dke djus ds rjhds ds vk/kkj ij Develop fd;k x;k Database System Hkh Hkfo’; esa fdlh
izdkj dh dksbZ ijs”kkuh iSnk ugha djsxkA
Effects of Poor Database Design
,d Database dk Design fdl izdkj ls fdlh Database System Application esa ,d cgqr
gh egRoiw.kZ Roll vnka djrk gS] bl ckr dks ge ,d lkekU; ls Business Example }kjk gh le> ldrs gSaA ge tks Business Example ys jgs gSa] mlesa ,d cgqr gh Poor Design dks
bl Business Example dks geus “Music Store” uke fn;k gSA bl Business esa ,d Music Store fofHkUu Titles ds CDs o DVDs dh Selling dk dke djrk gSA ;s Music Store Mail ls
vkus okys Orders ds vk/kkj ij Titles Selling dk dke djrk gSA bl Business Example esa tc Hkh dksbZ Customer fdlh Single Item dks Purchase djus ds fy, Order nsrk gS] Music Store dk ,d Employee fuEu Form dks Fill djds Customer ds Order dks Computer ij Data ds :i esa Store ;k Record dj ysrk gSA
pwafd ge ;s eku jgs gSa fd Music Store ij vkus okys Orders Mail }kjk vkrs gSa] blfy, ,d gh
City ls dbZ Customers Orders vk ldrs gSaA bl Music Store Software esa gj Customer dks Uniquely Identify djus ds fy, ,d Unique Number Assign fd;k x;k gSA gj
Customer dks Hkh Music Store }kjk Uniquely Identify fd;k tk ldrk gSA
tc Music Store esa Titles Distributor ls dksbZ u;k Title vkrk gS] rks Music Store dk ,d
Employee mu lHkh Customers dks Search djrk gS] ftUgksaus ml Title ds fy, igys ls gh
Order ns j[kk FkkA fQj og Employee mu Customers dh Computer esa Stored Order Data ds vk/kkj ,d List Create djrk gS vkSj Form ij fLFkr “Item shipped?” Check Box esa ,d ‘X’ Place dj nsrk gS] tks bl ckr dk Signal gksrk gS fd igys ls vk, gq, Order dks
iwjk dj fn;k x;k gSA
igyh utj esa ns[kus ij Music Store dk ;s Management dkQh lkQ lqFkjk o ljy yxrk
gSA FkksMs le; rd ;s Software dke Hkh Bhd rjg ls djrk gSA ysfdu ,d&nks lky ckn bl
Software ls Serious Problems iSnk gksus yxrh gSaA
Unnecessary Duplicated Data and Data Consistency Music Store Database esa cgqr lkjk Data ckj&ckj vuko”;d :i ls Duplicated Form esa
Input djuk iMrk gS vkSj ,d gh izdkj ds Data dks ckj&ckj fdlh Database esa Store djus
tkrk gSA fdlh Database esa ,d gh izdkj ds Data dks ckj&ckj Store djus dh izfØ;k dks
Data Redundancy dgk tkrk gSA
tc Hkh dksbZ Customer Music Store ij dksbZ Title Order djrk gS] mijksDr Form esa ml
Customer ds Order dks Record dj fy;k tkrk gSA fdl Customer us dkSulk Order Place fd;k gS] bl ckr dh tkudkjh j[kus ds fy, Order nsus okys Customer dk uke]
Address o Phone Number Hkh Order dh Information ds lkFk gh Database esa Store dj
fy;k tkrk gSA
vc pwafd ,d gh Customer ,d ls T;knk ckj Order dj ldrk gS] blfy, dksbZ ,d gh
Customer ftruh ckj Hkh fdlh Title ds fy, Music Store ij Order nsrk gS] gj ckj ml
Customer ds uke] Address o Phone Number dks Form ij Fill djds Order dh
Information ds lkFk Database esa Store dj fy;k tkrk gSA ftlls ml Customer dh
tc gekjs Database esa bl rjg ls Duplicated Form esa Data Store gks jgs gksrs gSa] rc gesa bl ckr dk /;ku j[kuk t:jh gks tkrk gS fd Duplication Form esa Store gksus okys lHkh
Data gj ckj leku :i esa gh Database esa Store gksaA
nwljs “kCnksa esa dgsa] rks fdlh Customer }kjk fn, tkus okys gj Order dks Music Store Application esa Store djrs le; gesa bl ckr dk /;ku j[kuk t:jh gksrk gS fd ml
Customer ds gj Order esa mldk uke] Address o Phone Number ,d tSls gh Store fd, tk,A
blh rjg ls ,d Single Title ds fy, ftrus Hkh Order Place fd, tkrs gSa] mu lHkh Orders esa Title dks ,d Hkh Character ds gsj&Qsj ds fcuk ,d tSlk Type djuk t:jh gksrk gSA blh
dkQh eqf”dy gks tkrk gSA T;knkrj Business Oriented Database Software Case Sensitive gksrs gSa] ftuesa Uppercase Letters o Lowercase Letters vyx&vyx Behave djrs gSaA
ge ;s eku ldrs gSa fd Music Store Form esa Order dh Entry djus okyk dksbZ Hkh Operator bruk Perfect Typist ugha gks ldrk] tks gesa”kk bl ckr dks /;ku j[k lds fd mlus fdl
Customer ds uke o irs esa dkSulk Character Capital Letter esa fy[kk Fkk vkSj dkSulk
gS] rks Application }kjk Generate gksus okyh Pending Orders dh List esa “Rahul” dk
Order Display ugha gksxk vkSj ;fn Typist “UMI 10” Character Combination dk iz;ksx
djrk gS] rks “Rohit” dk Order Display ugha gksxkA
bl fLFkfr esa ge le> ldrs gSa fd “Rahul” o “Rohit” nksuksa esa ls fdlh ,d ds Pending Order dh gh tkudkjh ;s Music Store Application ns ldrk gSA ftlls fdlh uk fdlh
Customer ds Order dh Request rks v/kwjh gh jgsxhA
gekjs Current “Music Store” Application esa bl ckr dks Ensure djus dh dksbZ O;oLFkk ugha
gS fd Database esa Data Hkys gh Duplicated Form esa Store gksa] ysfdu Duplicated Data Hkh Consisted Form ;kuh fo”oluh; :i ls Database esa Enter gksaxs vkSj mijksDr izdkj dh
Customer dks Hkst nsrk gS] rkfd mudk Customer ;s r; dj lds fd mls dkSu&dkSu ls Title Order djus gSaA bl Catalog Booklet esa cgqr lkjs Pages gks ldrs gSa vkSj gj Page dks
Music Store dk dksbZ Employee Lo;a “Copy Paste” dh izfØ;k }kjk rS;kj djrk gSA
vc ekuyks fd ge ;s pkgrs gSa fd ;s Catalog Booklet Database ds vk/kkj ij Lo;a gh rS;kj
gks tk,A pwafd fofHkUu izdkj ds Titles Database esa Stored gksrs gSa] blfy, ge Catalog Booklet dks Database ds vk/kkj ij rS;kj dj ldrs gSaA ysfdu fQj Hkh ge Current Database ds vk/kkj ij ;s dke ugha dj ldrs gSaaA blds nks dkj.k gSa%
fdlh Hkh Catalog esa fdlh Hkh Title ls lEcaf/kr fofHkUu izdkj dh Additional tkudkfj;ka gksrh
gSaA mnkgj.k ds fy, fdlh Title ds Singer, Music Director, Financer vkfn dh tkudkfj;ka
gks ldrh gSa vkSj Title ls lEcaf/kr dqN Extra Description gks ldrh gSaA
pwafd gekjs Music Store Database esa bu tkudkfj;ksa dks Store djus dh O;oLFkk ugha gS]
blfy, bl leL;k ds lek/kku ds :i esa ge gekjs Music Store ds Database dks Modify djds mlesa u, Fields Create dj ldrs gSaA ysfdu ;s rjhdk Hkh iwjh rjg ls Catalog Create djus esa l{ke ugha gks ldrkA D;ksafd ,d gh Title dks cgqr lkjs Customers Order dj ldrs
gSaA
bl fLFkfr esa gj Order ds lkFk Title dh fofHkUu Descriptions dks Computer esa Store djus
ls Data dh Redundancy c< tk,xh vkSj ;fn dsoy ,d gh Customer ds Order esa fdlh
Title dh Information dks Store fd;k tk, rks gesa”kk bl ckr dks /;ku j[kuk gksxk fd fdl
Title dh Extra tkudkfj;ksa dks fdl Customer ds Order esa Specify fd;k x;k gS] tks fd
nwljh leL;k ;s gS fd gekjs Music Store Application ds Database Management System
esa ,slh dksbZ O;oLFkk ugha gS] ftlls fdlh Title dks Advance esa gh Database esa Enter fd;k
tk ldsA tc rd dksbZ Customer ml u, Title dk Order Place ugha djrk gS] rc rd ml
Title dks Database esa Store ugha fd;k tk ldrk gS vkSj tc rd Title Database esa Store ugha gksxk] rc rd Updated Catalog Booklet Create ugha fd;k tk ldrkA
lkFk gh Customer rc rd ml Title dk Order Place ugha dj ldrk tc rd fd mls
Updated Catalog Booklet izkIr uk gks] D;ksafd mls u, Title dh tkudkjh Updated Catalog Booklet ls gh izkIr gksrh gSA bl leL;k dks Database Management dh Hkk’kk esa
“Insertion Anomaly” dgk tkrk gSA
Data Deletion Problems
gekjs bl Music Store Database Program ls tc fdlh Data dks Delete fd;k tkrk gS]
rc Hkh dqN leL;k,a lkeus vkrh gSaA ekuyks fd ,d Customer dsoy ,d Item dk Order nsrk gSA Order dks Process djus ds ckn ;kuh Order dh Entry Music Store ds Form }kjk
Database esa dj nsus ds ckn irk pyrk gS fd ml Item dks Manufacture djus okys
Manufacturer us ml Item dks Create djuk cUn dj fn;k gSA bl fLFkfr esa Music Store vius fdlh Hkh Customer dks og Item ugha Hkst ldrk] ftlus bl Out Of Stock Item ds
fy, Order fd;k gSA
vc pwafd Orders dh Entry Database esa igys gksrh gS] blfy, mu lHkh Customers ds
Order dh List esa ls bl Item dk Reference Database ls Delete djuk gksxk] ftUgksaus ml
Particular Item ds fy, Order fd;k gS] tks fd vc Available ugha gSA
pwafd ftu yksxksa us cgqr lkjs Items Order fd, gSa] muds Order dh List esa ls dsoy bl
Item dk Order fd;k Fkk] Database ls muds Order dh List esa ls bl Item dk
Reference Delete djus ij muds Order esa dksbZ Item ugha cpsxk] ftls ml Customer dks
Hkstk tk ldsA bl fLFkfr esa ,sls Customers dk Order Hkh Delete dj fn;k tk,xkA
vc pwafd fofHkUu Customers dh Information Hkh muds Order ds lkFk gh Database esa Store gksrh gS] blfy, ;fn fdlh Customer us ml Unavailable Item ds fy, Music Store dks First Time Order fn;k gks] rks tc ml Customer dk Order Delete gksxk] ml Order ds lkFk gh ml Customer dh Information Hkh Delete gks tk,xhA
bl fLFkfr esa Music Store ml Customer dks Hkfo’; esa dksbZ Catalog Booklet ugha Hkst
ldsxk vkSj Music Store dk ml Customer ls Link gh VwV tk,xk] D;ksafd ml Customer dk Address mlds Un-Fulfilled Order ds lkFk gh Delete gks pqdk gSA Database dh bl
Problem dks Database dh Hkk’kk esa “Deletion Anomaly” dgrs gSaA
ml Customer ds uke o City ds Pincode Number dks Use fd;k tkrk gSA
vc ekuyks fd ,d Customer ftl City esa jgrk gS] ml City dks NksMdj fdlh nwljs “kgj esa
pyk tkrk gSA bl fLFkfr esa mlh Customer dks Identify djus ds fy, fQj ls ,d u;k
Customer Number Create fd;k tk,xk] tks fd ml nwljh City ls lEcaf/kr gksxkA ftlls
gekjs bl Database esa ,d gh Customer ds nks ID gks tk,axs tks ,d gh Customer dks
Refer djsaxsA
ekuyks fd ,d Customer Music Store ij ,d Order Place djrk gS vkSj mlds ckn og
viuh City Change dj ysrk gSA vc ;fn og Customer viuh City Change dj ysus ds
ckn ;s tkuuk pkgrk gS fd mlds fdrus Order Music Store ij Pending gSa] ftlds Items dks Music Store us ml Customer dks Serve ugha fd;k gSA ml Customer ds Pending Orders dh tkudkjh izkIr djus ds fy, Music Store dk og Operator tks fd Music Store Software dks Operate djrk gS] ml Customer ls mldk Customer Number iwNsxk] rkfd
og ml Customer Number okys Customer dh dqy Transactions dh List izkIr dj ldsA
pwafd Customer vc nwljs “kgj esa jgrk gS] blfy, mldk Customer Number Change gks x;k gSA bl fLFkfr esa og vius Current Customer Number dh tkudkjh ml Operator dks
nsxkA ftldk eryc ;s gS fd bl “kgj esa vkus ls igys mlus Music Store ij ftrus Hkh
Order Place fd, gSa] mudh tkudkjh mls mlds Current Customer Number }kjk izkIr ugha gksxh] D;ksafd os Orders mlus vius iqjkus “kgj ls fn, Fks vkSj ml “kgj esa jgus ds dkj.k mldk
Customer Number nwljk FkkA bl fLFkfr esa og Customer ;s eku ldrk gS fd mldk
Order Music Store dks izkIr ugha gqvkA blfy, og Customer mlh Order dks fQj ls
Music Store ij Place dj nsxkA
bl fLFkfr esa ,d gh Customer ds ,d gh Order dh nks Entry Music Store Database esa gks tk,xh vkSj tc mu nksuksa Orders dks Music Store }kjk iwjk fd;k tk,xk] rc ,d gh
og Customer fQj ls Music Store dks Return dj nsxk vkSj Music Store dks
Transportation Charges Lo;a ogua djus gksaxsA
Entities and Data Relationships Database og LFkku gksrk gS] ftlesa Data dks uk dsoy Store fd;k tkrk gS] cfYd mu Store gksus okys Data ds chp dh vkilh Relationship dh Information dks Hkh Store fd;k tkrk
pkgs cgqr lkjs User Access dj jgs gksa ;k fQj pkgs ,d User Access dj jgk gks] User dks
bl ckr dh fpUrk djus dh t:jr ugha gskrh gS fd leL;k ls lEcaf/kr fofHkUu izdkj ds Data Computer esa fdl izdkj ls Store gks jgs gSaA User vius Database ls fofHkUu izdkj ds
Data dks dsoy mudh Relationship ds vk/kkj ij Access djds fofHkUu izdkj dh Database Related Information Generate djrk gSA
gkykafd User vius Data dks Logically Access djrk gS tcfd Data okLro esa Physically Store gksrs gSaA blfy, User o Database ds chp ds vkilh Conversation dks ,d nwljs
Form esa Translate djds ,d nwljs dks Available djokus dk dke ,d Software djrk gS]
ftls Database Management System Software (DBMS) dgk tkrk gSA
ge ftl Formal Way dks Use djds fofHkUu izdkj ds Data Relationship fdlh DBMS Software dks Express djrs gSa] ml Formal rjhds dks Data Model dgk tkrk gSA ge ftl
Relational Data Model dks bl iqLrd esa i<saxs] og dsoy ,d Formal Structure gh gksrk gSA
blls igys fd ge fdlh Database dks Design djsa] gesa Store fd, tkus okys fofHkUu izdkj
Related gksA mnkgj.k ds fy, fdlh Bank dk Account Hkh ,d Entity gks ldrk gS] D;ksafd
og ,d Physical Person ls gh lEcaf/kr gksrk gSA
gj Entity ds dqN Data gksrs gSa] tks ml Entity dks Describe djrs gSaA Entity ds bu Data dks Entity dk Attribute dgk tkrk gSA mnkgj.k ds fy, gekjs Music Store Application ds
lEca/k esa ,d Customer dks mlds Customer Number, First Name, Last Name, Street, City, State, Pincode o Phone Number }kjk Describe fd;k tkrk gSA blfy, ;s lHkh
Data Customer Entity ds Attributes gSaA
tc ge fdlh Database esa fdlh Entity dks Represent dj jgs gksrs gSa] rc okLro esa ge
fdlh Entity ds dsoy Attributes dks gh Computer esa Store dj jgs gksrs gSaA Attributes dk
gjsd Group tks fd fdlh ,d Single Real World Entity ds ,d mnkgj.k dks Describe djrk gS] ogh Attributes dk Group ml Entity ds nqfu;ka fd fdlh Hkh vU; Instance dks
Represent dj ldrk gSA
;kuh tks Attributes fdlh Rahul uke ds Customer dks Represent dj ldrs gSa] os gh
bldk eryc ;s gqvk fd gesa fdlh uk fdlh rjhds ls fdlh ,d Entity dks fdlh nwljs Entity ls vyx Represent djuk gksxk rkfd ge bl ckr ds fy, Ensure gks ldsa] fd ge ftl
Entity ds Data dks izkIr djuk pkgrs gSa] gesa mlh Entity ds Data izkIr gksaxsA
mnkgj.k ds fy, ekuyks fd Music Store ds Database esa Krishna uke ds nks Customers gSaA vc ;fn Krishna uke ds Customer ds Order dh tkudkjh izkIr djus ds fy, Music Store esa Searching dh tk,] rks Music Store Application fdl Krishna ds Data Return djsxk\ pwafd nksuksa Customers ds uke leku gSa] blfy, Music Store Application nksuksa gh Customers ds Orders dh List dks Display djsxkA
D;ksafd gekjs bl Application esa ,slk dksbZ rjhdk Use ugha fd;k x;k gS] ftlls Music Store Application okafNr Customer ds Orders dh gh List Display djsA bl fLFkfr esa Music Store }kjk Return fd;k tkus okyk Resultant Output Inaccurate gksxkA
Music Store Application esa bl leL;k ds lek/kku ds :i esa gj Customer dks ,d Unique Customer Number iznku fd;k x;k gS vkSj tc Hkh fdlh Customer ds Orders dh tkudkjh
izkIr djuh gksrh gS] rc ml Customer ds uke ds LFkku ij mlds Customer Number dk
iz;ksx fd;k tkrk gSA Entities ds Groups esa ls fdlh Particular Entity dks Identify djus dk
;s ,d cgqr gh Common rjhdk gS] D;ksafd fdlh Hkh Database esa nks Customers dks ,d gh
Customer Number iznku ugha fd;k tkrk gSA
Particular Entity Instance dks Identify djus ds fy, ge ,d nwljk rjhdk Hkh Use dj ldrs
gSa] ftlesa fdlh Customer ds First Name o Last Name dks mlds Telephone Number ds
lkFk ifjHkkf’kr dj ldrs gSaA fdlh Entity ds bu Attributes ds Combination }kjk Hkh
Customer dks Uniquely Identify fd;k tk ldrk gSA
ysfdu bl rjhds esa Hkh nks leL;k,a gSaA igyh ;s fd tc Identifier cMk o Tricky gksrk gS] rc blds fdlh Hkh fgLls dks Database esa Enter djrs le; Mistakes gks ldrh gSaA nwljh
leL;k ;s gS fd fdlh Hkh Customer dk Phone Number Change gks ldrk gS] ftlls ml
Constraint ,d ,slk fu;e ;k Rule gksrk gS] ftls Database Follow djrk gSA Database esa fofHkUu izdkj ds Constraints dks ykxw dj nsus ij Database mu Constraints ;k fu;eksa dk
ikyu djrk gS] ftlls Database esa Data ds Accurately o Consistently Store gksus dh
Guarantee gks tkrh gSA
Single-Valued and Multi-Valued Attributes pwafd ge ,d Relational Database Design dj jgs gSa] blfy, gekjs Data Model esa gj Attribute Single-Valued gksuk t:jh gksrk gSA bldk eryc ;s gqvk fd fdlh Entity ds fdlh
Instance ds gj Attribute esa dsoy ,d gh eku (Data) dks Store fd;k tk ldrk gSA
mnkgj.k ds fy, dksbZ Customer Entity vius fdlh Hkh Instance dks dsoy ,d Telephone Number Store djus dh lqfo/kk nsrk gSA ;kuh ge fdlh Hkh Customer dk dsoy ,d gh
Telephone Number Customer Table esa Store dj ldrs gSaA
ysfdu fdlh Customer ds ikl ,d ls T;knk Telephone gks ldrs gSaA ;fn ,d Customer ds ikl ,d ls T;knk Phone gSa vkSj og mu lHkh Numbers dks Database esa Include djokuk pkgrk gS] rks Customer Entity ;kuh Customer Table esa fdlh ,d Telephone Attribute File esa ,d ls T;knk Telephone Numbers dks Store ugha fd;k tk ldrk gSA bl
fLFkfr dks Customer Entity Handle ugha dj ldrk gSA
gkykafd fdlh Database dk Entity-Relationship Model Database dks Represent djus
okys Formal ;k Logical Data Model ls vyx ;k Independent gksrk gS] fQj Hkh ge Data ds Entity-Relationship Model dks Data ds Logical Model ds vk/kkj ij gh Develop djrs
fofHkUu Multi-Valued ekuksa dks ml u, Entity esa Hold djuk gksrk gSA
,d ls T;knk Phone Number gksus dh fLFkfr esa ge Phone Number uke dk ,d Entity Create dj ldrs gSaA bl Entity ds gj Instance esa ,d Attribute ml Customer Number dk gksxk] ftldk Phone Number Store fd;k tkuk gS vkSj nwljk Attribute ml Customer ds Phone Numbers dk gksxkA
;fn fdlh Customer ds pkj Phone Numbers gksa] rks bl Entity esa ml Customer ds pkj
Instance gksaxs] ftuesa Customer Number rks leku gksxk ysfdu Phone Numbers vyx&vyx gksaxsA bl Concept dks ge fuEukuqlkj Represent dj ldrs gSa] tgka igyk
Phone Number Entity gS] ftlesa gj Customer ds ,d ls T;knk Phone Numbers mlds
Customer Number ds lkFk Stored gSaA Customer Entity //================================================================== CustID FName LName City Dist. State
Telephone Number Entity esa Telephone Numbers dks Entity Identifier ds :i esa Use fd;k tk ldrk gSA blls Database esa fdlh izdkj dh dksbZ ijs”kkuh iSnk ugha gksrh gSA D;ksafd
bl Entity esa ge dsoy Phone Numbers dks gh Store dj jgs gSa vkSj ,d Phone Number vius vki esa Unique gksrk gSA tks Phone Number fdlh Customer Number 001 ds ikl gS
ogh Phone Number fdlh Customer Number 003 ds ikl ugha gks ldrkA
Multi-Valued Attributes ds lkFk leL;k ;s gksrh gS fd ;fn ge fdlh Entity esa Multi-Valued Attributes dks Store djuk pkgsa] rks gesa gj Value ds fy, ,d u;k Field Create djuk
gksxkA ;fn ge u, Fields Create dj Hkh ysrs gSa] rc Hkh ;s dHkh Hkh fuf”pr ugha fd;k tk
,slk djus ij Database dh Size Hkh c< tkrh gS] ftlls Database ij Searching Operations Hkh dkQh le; ysrk gSA ;kuh fdlh ,d Entity esa gh mlds fdlh Multi-Valued eku dks Store djus ds fy, ge mlh Entity dks Use ugha dj ldrs gSaA ;fn ge ,slk djrs gSa]
rks ge fofHkUu izdkj dh ubZ leL;kvksa esa Qal tkrs gSaA
gkykafd Theoretically ;s lEHko gS fd ge ,d ,slk Database Create dj ldrs gSa] tks fdlh
,d Attribute esa cgqr lkjs Data Store dj ldrk gS] ysfdu Practically bl izdkj ds
Database dks Implement djuk dkQh eqf”dy gksrk gSA
lkFk gh ;fn fdlh Database ds ,d gh Field esa ,d ls T;knk Data ;k ekuksa dks Store fd;k
tkrk gS] rks ml Database esa Searching Operation dsoy Sequential Form esa gh gks
ldrk gS] tks fd lcls Slowest Searching Process gksrk gSA
tcfd ;fn ,d Field esa dsoy ,d gh Single Value ;k Data dks Store fd;k tkrk gS] rks
ge ml Database ij Binary Searching dh Process dks Apply dj ldrs gSa] tks fd ,d
cgqr gh Fast Searching Process gksrk gSA
,d lkekU; fu;e ds :i esa ge tc Hkh dHkh fdlh Multi-valued Attribute dks Face dj jgs
gksrs gSa] rks og Attribute bl ckr dk ladsr gksrk gS fd gesa Entity esa vkSj u, Fields Created djus iM ldrs gSaA blfy, Same Attribute ds Multiple Values dks Handle djus dk lcls
ljy rjhdk ;gh gS fd ge ,d u;k Entity Create djsa vkSj Same Attribute ds mu lHkh
Values dks ,d Instance dh rjg ml Entity esa Store djsaA
Identifying Problem Related Entities ftu leL;k ls lEcaf/kr okLrfod Entity dks Identify djuk dbZ ckj dkQh Confusing gksrk gSA ;fn ge gekjs Music Store ds gh mnkgj.k ds vk/kkj ij le>sa] rks D;k ge Music Store dks Entity ds :i esa Identify dj ldrs gSa\ ugha] ge ,slk ugha dj ldrsA
D;ksafd Music Store rks mu Entities dk ,d iwjk Collection gS] ftUgsa Music Store Handle djrk gSA Entity rks okLro esa Music Store ds os Items gSa] ftUgsa Database }kjk Manage djuk gSA
bl ckr dks Bhd ls le>us ds fy, ge ,d mnkgj.k ysrs gSaA ekuyks fd ge Music Store dks
gh ,d Entity ds :i esa Identify dj ysrs gSaA vc bl Entity dks Represent djus ds fy, gesa
blds fofHkUu Attributes dk irk djuk gksxk tks fd Music Store ds Items Numbers, Item Titles, Item In Stock, Retail Price vkfn gksaxsA
ysfdu pwafd ge iwjs Music Store dks gh ,d Single Entity ds :i esa Describe dj jgs gSa]
blfy, gesa blds gj Attribute esa Multiple Values dks Store djuk gksxk vkSj tSlk fd geus
igys crk;k fd fdlh Hkh Relational Database esa dksbZ Hkh Attribute Multi-Valued ugha gks ldrk] blfy, ge Music Store dks ,d Single Entity ds :i esa Identify ugha dj ldrs gSa]
,d vkSj mnkgj.k ns[krs gSa] ekuyks fd dksbZ Doctor vius lHkh Patient dh Medical History dks Maintain djrk gSA fdlh Music Store ds Inventory Program dh rjg gh Medical History Hkh ,d rjg dk ,d ls T;knk Entities dk Collection gSA ,d Medical History Appointments o mu Appointments ds nkSjku gksus okyh ?kVukvksa }kjk curk gSA
blfy, ;s History okLro esa Appointment Entities o Medical Treatment Entities ds
Instances dk Collection gS] uk fd Lo;a ,d Entity gSA “History” rks og Output gS ftls
ldrs gSaA ER Diagrams ds dbZ rjhds izpfyr gSa] ysfdu nks rjhdksa dks lcls T;knk Use fd;k
tkrk gSA
igyk rjhdk Dr. Peter P. S. Chen us Develop fd;k FkkA blfy, bl Data Modeling Diagram dks ER Chen uke fn;k x;k gSA nwljk rjhdk James Martin o Clive Finkelstein us Develop fd;k gS vkSj bls Information Engineering (IE) esa Use fd;k tkrk gSSA
Entities and Attributes for Music Store Application gekjs Music Store Database ds Order Entry Form ls gh gesa mu eq[; Entities dk irk
py tkrk gS] ftUgsa gesa Music Store Database esa Manage djuk gSA
gkykafd tc ge Database Design Process dks vkxs c<krs gSa] rc Database Design esa vU; Additional Entities dh Hkh t:jr iMrh gSA gekjs Music Store Database ls lEcaf/kr
eq[;&eq[; Entities Customer, Order, Distributor, Actor, Producer o Item gSa vkSj bu
Entities ls lEcaf/kr os Attributes ftUgsa Database esa Store djuk gSa] mUgsa fuEukuqlkj
Information Engineering Diagram }kjk n”kkZ;k x;k gS%
Attribute esa fdl rjg ds eku Store gks ldsaxsA ,d Domain cgqr NksVk Hkh gks ldrk gSA
mnkgj.k ds fy, ftu Population ls lEcaf/kr Database esa Male/Female dks Represent djus ds fy, Gender Attribute esa dsoy M/F Character dks gh Store djus dh t:jr gksrh
gSA tcfd ftu Customer dk uke Store djus ds fy, Name Attribute esa cgqr lkjs
Characters dks Store djuk iMrk gSA
,d Database Management System (DBMS) ,d Domain Constraint ds Through ,d
Domain Enforce djrk gSA mlds ckn tc Hkh Database esa dksbZ Data ;k eku Store fd;k
tkrk gS] og DBMS Software ml Domain Constraint ds vk/kkj ij ;s r; djrk gS fd
mnkgj.k ds fy, ;fn ftu Customer dh Birth Date dks Store djus ds fy, Database esa DOB Attribute dks Date/Time Domain Constraint ls dks Set fd;k x;k gS] rks DBMS Software ml Attribute esa dsoy mlh Data dks Store djsxk tks Date/Time Format dk
gksxkA
“ks’k ftu Hkh vU; Domain (Data Type) ds Data dks og DBMS Software Database esa Store ugha djus nsxk ;gka rd fd tc ge Date/Time Domain Constraint dks ftu
Attribute ds lkFk Set djrs gSa] rc ge ml Attribute esa 30 February tSlh ftu xyr Date dks Hkh Store ugha dj ldrs gSaA
Documenting Domains ER Diagram dk tks Common Format Use fd;k tkrk gS] mlesa Domain dks Specify djus dh dksbZ lqfo/kk ugha gksrh gS] cfYd ml Diagram ls ,d Document Associated jgrk gS] ftls Data Dictionary dgrs gSaA Data Dictionary ds ckjs esa ge vkxs foLrkj ls i<ssaxsA ge
Chen ds ER Model esa gj Attribute ds uhps ml Attribute ds Domain dks Specify dj
ldrs gSaA
Practical Domain Choices Music Store ds Entities ds Attributes ds fy, ftu Domains dks Choose fd;k tkrk gS]
os Theoretically mu DBMS Softwares ls Independent gksus pkfg,] ftUgsa ge Music Store Database dks Develop djus ds fy, Use djsaxsA
mnkgj.k ds fy, ;fn ge ftu Employee dh Salary dks ;fn Character Form esa Store fd;k tk,] rks ge ml Employee dk PF, DA, HRA vkfn Calculate ugha dj ldrs gSa]
D;ksafd Character Domain ij ftl izdkj dk Arithmetical Operation Perform ugha fd;k
tk ldrkA
blh rjg ls ;fn ge ftu Attribute esa Date ;k Time Store djuk pkgsa] rks gesa DATE ;k
TIME Domains dks gh Use djuk pkfg,A ;fn ge ftl Date dks Store djus ds fy,
Character Format dk iz;ksx djrs gSa] rks ge Date ls lEcaf/kr fofHkUu izdkj dh leL;kvksa esa
Qal tk,axsA
mnkgj.k ds fy, ekuyks fd ge nks Dates 01/11/2009 o 10/11/2000 dks Character Domain dk iz;ksx djds Database esa Store djrs gSaA vc ;fn ge DBMS ls ;s irk djuk
pkgsa fd dkSulh Date igys vkrh gS rks nksuksa gh Dates Character Format esa Store gksus ds
dkj.k DBMS bu nksuksa Dates esa ls Alphabetical Order ds vk/kkj ij igys vkus okyh Date dks Calculate djsxk vkSj gesa Result ds :i esa 01/11/2009 iznku djsxk] D;ksafd
Alphabetical Order esa 01, 10 ls igys vkrk gS vkSj ge le> ldrs gSa fd ;s ,d xyr
Result gSA
;fn ge Character Form esa gh Date dks Store djds ;s tkuuk pkgsa fd dkSulh Date igys
vkrh gS] rks gesa bl Date dks YYYY/MM/DD Format esa Database esa Store djuk gksxk vkSj
bl Format dh Date dks lkjh nqfu;ka esa cgqr gh Rarely Use fd;k tkrk gSA tcfd ;fn ge
bu Dates dks Store djus ds fy, DATE Domain dk iz;ksx djrs gSa] rks gesa Date ls
Database ds fofHkUu Entities ds chp eq[;r% rhu rjg dh Relationship gks ldrh gSa% One To One Relationship, One To Many Relationship o Many To Many Relationship
blls igys fd ge bu Relationships dks le>sa gesa ,d ckr /;ku esa j[kuh gksrh gS fd fdlh
Database esa ftruh Hkh Relationships Stored gksrh gSa] os lHkh Relationships Entities ds
Instances ds chp gksrh gSaA
mnkgj.k ds fy, gekjs Music Store Example ds vk/kkj ij dksbZ Customer mu Items ls
Related gksrk gS] ftudk ml Customer us Order fn;k gSA ;kuh Customer Entity dk gj
Instance Item Entity ds Order fd, x, Item Instance ls Related gksrk gSA
ge ;gka ftl Relationship ds ckjs esa ppkZ dj jgs gSa] og Relationship iwjh rjg ls fdlh
Database dk Conceptual Representation gS vkSj bl Relationship dk Data ds Actual Physical Storage ls dksbZ lEca/k ugha gksrk gSA
tc ge Data Relationship dks ER Diagram ;k IE Diagram }kjk Document djrs gSa] rc
ge fofHkUu Entities ds chp dh Relationship dks Show djrs gSaA bu Diagrams esa ge mu Possible Relationships dks Show djrs gSa tks Database esa Allowable gksrh gSaA ge tc
gksrk gS fd Database ls Related gj Entity vkilh Relationship esa Involved gksA
mnkgj.k ds fy, Music Store Database fdlh Hkh Customer dh Information dks
Database esa Store dj ldrk gS] Hkys gh ml Customer us Music Store dks fdlh Hkh Item
ds fy, dksbZ Hkh Order uk fn;k gksA ;gka ;s t:jh ugha gS fd ogh Customer Music Store Database esa Store gks ldrk gS] ftlus dksbZ Music Store dks fdlh Title ds fy, dksbZ
Order fn;k gksA
One To One Relationships
ekuyks fd fdlh NksVs ls “kgj esa dsoy ,d gh Airport gS vkSj fdlh Database esa og “kgj o Airport nksuksa gh ,d Entity ds :i esa Involved gSaA bl fLFkfr esa City o Airport nksuksa gh ml
Database esa nks vyx Entities ds Instance ds :i esa Represent gksaxsA
vr% City o Airport ds chp One To One dh Relationship dks bl rjg ls Express fd;k
tk ldrk gS fd Airport dsoy ,d City esa gh Situated gS vkSj ml City esa dsoy ,d gh
Airport gSA
;s mnkgj.k One To One Relationship dk ,d vkn”kZ mnkgj.k gS] D;ksafd bl Database esa fdlh Hkh le; ,d City ls dsoy ,d gh Airport Related gksxk vkSj ml ,d Airport ls dsoy
,d gh City Related gksxhA gkykafd fdlh “kgj esa ,d ls T;knk Airports gks ldrs gSa] ysfdu
ge ;gka ,d cgqr gh NksVs “kgj ds Airport Database dks Manage dj jgs gSa vkSj ge ;s eku
jgs gSa fd fdlh Hkh NksVs “kgj esa ,d ls T;knk Airport ugha gks ldrs gSaA
;fn gekjs ikl nks Entities A o B ds nks Instances Ai o Bi gksa] rks bu nksuksa Entities ds
Instances ds chp One To One dh Relationship dsoy rHkh lEHko gS] tc fdlh Hkh le;
Ai Entity B ds Zero ;k One Instance ls Related gks vkSj Bi Entity A ds Zero ;k One Instance ls Related gksA
fdlh Hkh Business Database Application esa One To One dh Relationship cgqr gh Rare Case esa curh gSA mnkgj.k ds fy, ekuyks fd gekjk Music Store ,d u, Distributor ls Dealing djuk r; djrk gSA Music Store ml u, Distributor dks dsoy ,d gh Special Title dk Order nsrk gSA
vc ;fn ge ml u, Distributor dks vius Database esa LFkku nsa] rks ge ns[krs gSa fd ml u,
Distributor Entity dk Instance Music Store ds Item Entity ds dsoy ,d Instance ls
Related gksrk gSA blfy, ;gka ij ml u, Distributor o Item ds chp One To One dh
Relationship curh gSA
vc ;fn Music Store ml u, Distributor dks dbZ vkSj Titles ds Order nsrk gS] rks ;gka ;s fu;e Violate gks tkrk gS fd og u;k Distributor Music Store ds dsoy ,d gh Item ls
Related gSA bl fLFkfr esa ml u, Distributor Entity ds Instance o Item Entity ds
Instance ds chp One To One ds LFkku ij One To Many dh Relationship cu tkrh gSA
D;ksafd vc og u;k Distributor Music Store ds ,d ls T;knk Items ds Titles ls Related gks tkrk gSA
blh rjg ls ;fn ge Music Store Database esa Credit Card uke dk ,d vkSj Entity Create djrs gSa] ftlesa mu Credit Cards ds Data dks Hold fd;k tkrk gS] ftudk iz;ksx os
Customer viuh m/kkjh pqdkus ds fy, djrs gSa] ftudk dqN iSlk Music Store esa cdk;k gSA
pwafd gj Customer dsoy ,d gh Credit Card ls viuk iSlk pqdkrk gS] blfy, ;gka ij Hkh
Customer Entity ds Instance o Credit Card Entity ds Instance ds chp One To One dh Relationship Create gksrh gSA
Credit Card Entity ds fy, Credit Card dk Number, Type o Expiration Date Attributes gks ldrs gSaA ;fn ge ;s eku ysa fd gj Customer ds ikl dsoy ,d gh Credit Card gksrk gS] rks pwafd Credit Card ds fdlh Hkh Attribute dk eku Multi-Valued uk gksus dh otg ls gesa
Credit Card dks ,d vyx Entity ds :i esa Represent djus dh t:jr ugha gSA ge Credit Card ds fofHkUu Attributes dks Customer dh Information ds lkFk Store dj ldrs gSaA
ge tc Hkh dHkh fdlh Database ds lUnHkZ esa One To One Relationship dks Identify djrs
gSa] rks gesa /;ku ls ;s ns[k ysuk pkfg,] fd dgha ge One To Many dh Relationship dks rks
One To One dh Relationship ugha eku jgs gSa ;k dgha ,d gh Entity dks rks nks Entity ds
:i esa Represent djus dh dksf”k”k rks ugha dj jgs gSaA
One To Many Relationships fdlh Database ds fofHkUu Entities ds chp dh ;s ,d cgqr gh Common Relationship gksrh gSA okLro esa Maximum Database esa ftruh Hkh Relationships gksrh gSa] muesa ls T;knkrj
One To Many dh gh Relationship gksrh gSaA One To One dh Relationship rks Rare Case esa gh curh gSA
Music Store Database ds lUnHkZ esa Hkh Database ds fofHkUu Entities ds Instances ds
chp ;s gh Relationship Define gks jgh gSA mnkgj.k ds fy, Music Store cgqr lkjs Titles ds
fy, Distributors dks Order ns ldrk gS vkSj Music Store ,d Title dk Item dsoy ,d gh
Distributors ls izkIr djrk gSA
blh rjg ls ,d Customer Music Store ij dbZ Orders Place dj ldrk gS ysfdu ,d
Order dsoy ,d gh Customer nsrk gSA tSls Order Number 001 fdlh Rahul uke ds
Customer us fn;k gks] rks blh Number dk dksbZ nwljk Order fdlh nwljs Customer }kjk Music Store dks ugha fn;k tk ldrk gSA
;fn gekjs ikl nks Entities A o B ds nks Instances Ai o Bi gksa] rks bu nksuksa Entities ds
Instances ds chp One To Many dh Relationship dsoy rHkh lEHko gS] tc fdlh Hkh le;
Ai Entity B ds Zero, One ;k More Instances ls Related gks vkSj Bi Entity A ds Zero ;k One Instance ls Related gksA
One To Many dh Relationship dks ,d Family Relationship ds :i esa vkn”kZ rjhds ls
Represent fd;k tk ldrk gSA ,d eka o mlds cPapksa ds chp One To Many dh
Bhd blh rjg ls ;fn ge ,d vkSj mnkgj.k ns[ksa rks ,d Computer o mlds CPU ds chp Hkh
One To Many dh Relationship dks Represent fd;k tk ldrk gS] tgka ,d CPU dks
dsoy ,d gh Computer esa Install fd;k tk ldrk] tcfd ,d Computer esa ,d ls T;knk
CPU dks Install fd;k tk ldrk gSA
;fn blh Concept dks ge Music Store ds Database ij Apply djsa] rks ge dg ldrs gSa
fd Music Store o mlds Distributor ds chp One To Many dh Relationship gksrh gS] tgka
Music Store ,d Title ds fy, fdlh ,d gh Distributor dks Order ns ldrk gS] tcfd ogh
Title Music Store dks ,d ls T;knk Distributor iznku dj ldrs gSaA
,d ckr /;ku j[ksa fd tc ge Data Relationships dks Specify dj jgs gksrs gSa] rc ge lHkh
lEHko Relationships dks Indicate dj jgs gksrs gSa vkSj ;s t:jh ugha gksrk gS fd lHkh Entities ds lHkh Instances gj Documented Relationship esa Hkkx ysaA ;kuh gekjs Music Store Database ds vk/kkj ij ;s t:jh ugha gS fd dksbZ Distributor Instance fdlh Item Entity ds
Zero, ,d ;k ,d ls T;knk Instances ls Related gksA
Many To Many Relationships ;s Relationships Hkh dkQh Common Relationships gSaA ;fn ge Music Store Database ds lUnHkZ esa bl Relationship dks ifjHkkf’kr djsa] rks Customer Entity o Item Entity ds chp
Many To Many dh Relationship gksrh gSA D;ksafd ,d Customer ,d ls T;knk Titles dk
Order ns ldrk gS vkSj ,d gh Title ds fy, ,d ls T;knk Customer Order ns ldrs gSaA
blh rjg ls ,d Distributor o ,d Item ds chp Hkh Many To Many dh Relationship gks ldrh gS] ftlesa ,d gh Distributor dks ,d ls T;knk Title ds fy, Order fn;k tk ldrk gS
vkSj ,d gh Title dks ,d ls T;knk Orders esa Place fd;k tk ldrk gSA
;fn gekjs ikl nks Entities A o B ds nks Instances Ai o Bi gksa] rks bu nksuksa Entities ds
Instances ds chp Many To Many dh Relationship dsoy rHkh lEHko gS] tc fdlh Hkh
le; Ai Entity B ds Zero, One ;k More Instances ls Related vkSj Bi Entity A ds
Zero, One ;k More Instances ls Related. Many To Many Relationship Database Design esa nks cMh leL;k,a iSnk djrk gS] ftUgsa vkxs foLrkj ls le>k;k x;k gSA
bl fLFkfr esa ,d Customer Entity dk dksbZ Instance Item Entity ds fdlh Hkh Instance ls
Related ugha gksrk gS ;k nwljs “kCnksa esa dgsa rks ,d Customer Entity dk dksbZ Instance Item Entity ds Zero Instance ls Related gksrk gSA
gkykafd ,d Customer tc dksbZ Order Place ugha djrk gS] rc Hkh ml Customer dh
Database esa Entry dh tk ldrh gS] ysfdu ;fn ge bl Concept dks Reverse Order esa ysa] rks ,slk lEHko ugha gks ldrkA ;kuh gj Order dk fdlh ,d Customer ls Related gksuk t:jh gksrk gSA fcuk fdlh Customer ds Order fn, gq,] Music Store Database esa ,d
Order Place gh ugha gks ldrk] D;ksafd fdlh Hkh Order dks Place djus ds fy, ,d
Customer t:j gksuk pkfg,A
;fn ge bl Discussion ds vk/kkj ij le>sa rks ;gka Order ,d Weak Entity gS] D;ksafd ;s
,d ,slk Entity gS] ftls Database esa rc rd Store ugha fd;k tk ldrk gS] tc rd fd ml
Order Instance ls Related dksbZ nwljk Entity Instance ml Database esa Present uk gks vkSj ml Order ls Related uk gksA
Customer Entity dk ,d Instance Zero, One ;k More Orders ls Related gks ldrk gSA
fQj Hkh ,d Order dk dsoy ,d vkSj flQZ ,d gh Customer Entity Instance ls Related gksuk t:jh gksrk gSA Weak Entity ds fy, Zero Option Available ugha gksrk gSA bl fLFkfr esa
Customer o Order ds chp dh Relationship ,d t:jh ;kuh Mandatory ;k
Compulsory Relationship gS] ftls Database dks Bhd ls Manage djus ds fy,
Weak Entities o ml Weak Entity ls Associated Mandatory Relationship Entity dks
Identify djuk dkQh egRoiw.kZ gksrk gSA
budk Database ij vkilh izHkko tkuus ds fy, ekuyks fd ge ,d ,slk Order Database esa Store djrs gSa] ftlls Belonged Customer dk irk ugha gSaA bl fLFkfr esa ge ml Order esa
Specify fd, x, Items dks dHkh Hkh fdlh Customer rd Ship ugha dj ldrs gSa] D;ksafd ml
Order esa ml Customer dh tkudkjh gh ugha gksrh gS] ftls ml Order ds Items Ship djus
gSaA
blh Concept ds vuqlkj ge Order o Order Lines ds chp dh Relationship dks Hkh One To Many ds Relationship ds :i esa Define djrs gSa] D;ksafd ge ugha pkgrs gSa fd fcuk fdlh
Order ls Related gq, dksbZ Order Line Database esa Store gksA Order Line fdlh Order ij fLFkr fdlh Specific Item dks Refer djrk gSA ;kuh ,d Order Line rc rd
Meaningless gksrk gS] tc rd fd ge ;s ugha tkurs gSa fd og Order Line fdl Order ls
Belong djrk gSA
blds ctk; ge Music Store ij miyC/k fdlh Hkh Item dks Database esa Store dj ldrs
gSa] tcfd gesa ;s tkuus dh t:jr ugha gksrh gS fd ml Item dks fdl Supplier us Hkstk gS]
tcfd ge ;gka ij ;s eku jgs gSa fd gj Item fdlh ,d Supplier ls vkrk gSA bl fLFkfr esa
Supplier o Item ds chp okLro esa Zero To Many dh Relationship gks tkrh gSA
Documenting Relationships Chen o IE nksuksa gh rjhdksa ds ER Diagrams esa Relationship dks vyx rjhdksa ls
Represent fd;k tkrk gSA nksuks gh rjhdksa ds vius Qk;ns o dfe;ka gSaA Chen Method esa Relationship dks Represent djus ds fy, Diamond Symbol dk iz;ksx fd;k tkrk gS vkSj
Entities ds chp Relationship ds Type dks Represent djus ds fy, Arrow Based Lines dk iz;ksx fd;k tkrk gSA mnkgj.k ds fy, fuEu ER Diagram dks nsf[k,%
bl Diagram esa ge Customers o Orders ds chp dh Relationship dks ns[k ldrs gSaA
Customer dh rjQ tks Single Arrow Point dj jgk gS og Arrow Indicate djrk gS fd ,d
Order dsoy ,d gh Customer ls Belong dj jgk gSA tcfd Orders Entity dh rjQ dk
Double Arrow bl ckr dks Indicate djrk gS fd ,d Customer ,d ls T;knk Orders Place dj ldrk gSA Diamond ds chp fy[kk x;k “kCn Relationship ds lEca/k esa dqN
tkudkjh iznku djrk gSA
Chen Model esa nks Alternative Styles gSaA igys Style esa Arrows dks Numbers o Letters ls Replace dj fn;k tkrk gSA Number “1” ;s Indication nsrk gS fd ,d Order fdlh ,d
Customer ls vkrk gSA tcfd “M” ;k “N” Character ;s Indication nsrk gS fd Customer
Chen Method ds vykok ge Information Engineering Method dks Use djds Hkh ER Relationship Model dks Create dj ldrs gSaA IE Method esa Line ds End ds vk/kkj ij gh
rd fdlh Producer dks Database esa Store ugha djrs gSa] tc rd fd og
Producer fdlh Item ls Related uk gksA Producer o Items ds chp dh
Relationship dks Optional Means ds :i esa Specify djds ge fcuk Item dh
Information Store fd, gq, Hkh Producer dh Information dks Database esa Store dj ldrs gSaA
bl Design esa Notice djus okyh tks lcls cMh pht gS oks ;s gS fd bl Design esa rhu Many To Many Relationships gSa] tks fd Order To Item, Actor To Item o Producer To Item ds Entity ds chp gSA blls igys fd ge bl Data Model dks fdlh Relational Database ij Map djsa] bUgsa fdlh vU; rjhds ls Handle djuk gksxk] D;ksafd fdlh Hkh
Relational Database esa ge Many To Many Relationship dks Directly Map ugha dj
ldrs gSaA
Dealing with Many To Many Relationships tSlkfd geus igys crk;k gS fd Many To Many Relationship ds lkFk dqN vyx izdkj dh
leL;k,a gSaA lcls igyh leL;k rks ;gh gS fd dksbZ Hkh Relational Data Model Many To Many Relationship dks Directly Handle ugha dj ldrk gSA fdlh Relational Data Model esa ge dsoy One To One ;k One To Many Relationship dks gh Handle dj ldrs gSaA
bldk eryc ;s gqvk fd geus Music Store Database esa ftl Many To Many Relationship dks Identify fd;k gS] mUgsa One To Many Relationships ds Collections ds
:i esa Convert djds Relational Data Model esa Use djuk gksxk] rkfd ge bUgsa ,d
Relational DBMS esa Use dj ldsaA
nwljh leL;k FkksMh T;knk tfVy gSA bls le>us ds fy, ekuyks fd Music Store fdlh
Distributor dks dksbZ Order nsrk gS vkSj Music Store ij dksbZ Customer Order Place djrk gSA blfy, Order o Item ds chp Many To Many dh Relationship curh gS] D;ksafd
gj Order esa ,d ls T;knk Items Appear gks ldrs gSa vkSj ckn esa gj Item dbZ Orders ij Appear gks ldrk gSA tc dHkh Music Store fdlh Item ds fy, dksbZ Order Place djrk gS]
rc Item ds Copies dh la[;k Music Store dks izkIr gksus okyh Copies dh la[;k ls fHkUu
gks ldrh gSA ;kuh gks ldrk gS fd Music Store fdlh Item ds pkj Copy izkIr djuk pkgrk
gks tcfd Stock dh deh ds dkj.k mls og Item dsoy rhu gh izkIr gksA
vc loky ;s gS fd Order fd, x, Item dh Quantity dks dgka Store djuk pkfg,\ D;ksafd ;s
Quantity Order Entity dk fgLlk (Attribute) rks gks ugha ldrk D;ksafd Quantity ml Item
ij Depend djrh gS] ftls Music Store Order dj jgk gSA blh rjg ls ;s Quantity Item
bl fp= esa rhu Order Instances gSa vkSj rhu gh Item Instances gSaA igyk Order (Order #1) Customer Number #0985 us fn;k gS vkSj bl Order esa mlus dsoy ,d gh Item ( item #09244) dk Order fn;k gSA
nwljs Order (Order #2) Customer #0985 us fn;k gS vkSj bl Order esa mlus ftu nks Items dk mYys[k fd;k gS] mudk Number #02944 o #10101 gSA ;kuh nwljs Order esa Item Number #02944 rks fQj ls Appear gks gh jgk gS lkFk gh Item Number #10101 Hkh Appear gks jgk gSA
rhljk Order tks fd Order #3 gS] og Customer Number #1212 us Place fd;k gS vkSj
blesa Hkh nks Items Item Number #10101 o Item Number #00250 dk Order fn;k x;k gSA
bl fp= esa ge ns[k ldrs gSa fd rhu Customers us rhu Orders Place fd, gSa vkSj rhuksa
Orders esa dqy ikap Items dks Order fd;k x;k gSA bldk eryc ;s gS fd ;fn rhuksa Orders dks iwjs fd, tk,a] rks Item Number #02944 dh nks Copies, Item Number #10101 dh nks
Copies o Item Number #00250 dh dsoy ,d Copy ;kuh dqy ikap Copies Sell gksaxhA
bl Diagram ds chp dk fgLlk gh og Composite Entity gS] tks fd gj Order dks fdlh
,d Specific Item ls Connect dj jgk gSA gekjs bl Example Diagram esa dqy ikap
Instances gSa] ftUgsa ge “Line Items” dgsaxsA ;s Line Item Entities, Order o Item ds chp
bl Diagram esa ge ns[k ldrs gSa fd gj Order izR;sd Item ds fy, dsoy ,d Line Item Instance ls Related gSA nwljs rjhds ls ns[ksa rks izR;sd Item gj Order ij Appear gksus ds
fy, fdlh ,d Line Item Instance ls Related gSA
bl Diagram ds vk/kkj ij izR;sd Line Item Instance ,d vkSj flQZ ,d Order ls
Related gS lkFk gh ogh Line Item ,d vkSj flQZ ,d Item ls Related gSA ifj.kkeLo:i ,d
Order o mlds Line Items ds chp One To Many dh Relationship gS] D;ksafd ,d Order dbZ Line Items ls Related gS vkSj Item og Order, ftl ij og Item Appeared gS] ds
chp One To Many dh Relationship gS D;ksafd ,d Item ,d ls T;knk Line Items ij Appear gSA
bl rjg ls bl Diagram esa ge ns[k ldrs gSa fd ,d Composite Entity dh mifLFkfr ls
Original Many To Many dh Relationship nks One To Many dh Relationship esa
Convert gks jgh gSA ;fn gekjs Database ls lEcaf/kr dksbZ Relationship Data gS] rks ml
Data dks Store djus ds fy, ge bl Composite Entity esa gh ml Data ds fy,
Appropriate Attribute Create dj ldrs gSaA
mnkgj.k ds fy, Order fd, x, Item dh Quantity dks Store djus ds fy, bl Composite Entity esa Quantity uke dk Field ;k Attribute Create dj ldrs gSaA blds lkFk gh ge bl
Composite Entity esa bl ckr dh tkudkjh j[kus ds fy, ,d Flag Attribute Create dj
ugha vkSj ;fn Ship fd;k tk pqdk gS] rks Shipping Date dks Store djus ds fy, Shipping Date Attribute dks Hkh blh Composite Entity esa ,d Field ds :i esa Specify fd;k tk
ldrk gSA
Chen ds ER Method esa Composite Entity dks ER Diagram esa Draw djus ds fy,
fuEukuqlkj Symbol dk iz;ksx fd;k tkrk gS] tcfd Information Engineering Method esa Composite Entity dks ER Diagram esa Represent djus dk dksbZ rjhdk ugha gSA
Music Store Database ds lHkh Many To Many Relationships dks Eliminate djus ds fy,
gesa gj Many To Many Relationship dks ,d Composite Entity }kjk nks One To Many Relationships esa Convert djuk gksxkA
tSlkfd ge gekjs Music Store Database ds fiNys IE ER Diagram esa ns[k ldrs gSa] mlesa
rhu Many To Many Relationships gSa] blfy, bu rhuksa Many To Many Relationships dks Remove djus ds fy, gesa rhu Composite Entities dks fuEukuqlkj Create djuk gksxk%
1 Order Lines Order Lines Entity ,d Item dks ,d Order ij Represent djrk gSA gj Order dh dbZ “Order Lines” gks ldrh gSa tks fd vyx&vyx Items ls Connect gksa] ysfdu Order Line ,d vkSj flQZ ,d Order ij Appear gks ldrk gSA blh rjg ls
,d Order Line esa ,d vkSj flQZ ,d Item Appear gks ldrk gS ysfdu ,d gh Item
,d ls T;knk Order Lines esa Appear gks ldrk gS vkSj izR;sd Item fdlh Different Order ls Connected gksrk gS D;ksafd ,d gh Item ds fy, ,d ls T;knk Orders Place fd, tk ldrs gSaA
2 Performance Performance Entity ;s Represent djrk gS fd ,d Actor ,d Film esa Appear gksrk gSA gj Performance ,d vkSj flQZ ,d Film ds fy, gksrh gS] tcfd ,d Film
esa ,d ls T;knk Performance gks ldrh gSa] D;ksafd ,d Film esa ,d ls T;knk Actor gks ldrs gSaA blh rjg ls ,d Actor izR;sd Film esa ,d Performance ls Related gksrk gS] ysfdu ,d Film esa dsoy ,d vkSj flQZ ,d Performance ls Related gksrk gSA
3 Production Production Entity ;s Represent djrk gS fd ,d Producer ,d Film ij dke
Store ij Hkst ldrk gSA ,slk t:jh ugha gS fd tks Employee ftl Store ds fy, fu;qDr
fd;k tk,xk] og gesa”kk mlh Store ij fu;qDr jgsxkA gj Employee gesa”kk ,d gh Store ds
fy, fu;qDr fd;k tkrk gS] rks Employee o Store ds chp One To Many dh Relationship Identify gksrh gS vkSj ;fn gj Employee izR;sd Store ij FkksMk&FkksMk le; O;rhr djrk gS]
rks Employee o Store ds chp Many To Many dh Relationship Identify gksrk gSA
fLFkfr esa dkSulk Design lgh gS] ;s ckr ml Organization ds dke djus ds rjhds ij fuHkZj
djrk gS] fd og Organization vius Business dks fdl rjg ls Operate djrk gSA
;kuh bl ckr ls dksbZ QdZ ugha iMrk gS fd ge Database Design ds lEca/k esa fdruk T;knk
tkurs gSa] cfYd ge rc rd ,d vPNk Database Create ugha dj ldrs gSa] tc rd gekjk
Database fdlh Business Environment dh fofHkUu Relationships dks Accurate rjhds ls
Reflect ugha djrk gSA
Data Modeling and Data Flow Data Model Design djrs le; tks lcls T;knk Common Mistakes dh tkrh gSa] oks Data Model o Data Flows ds chp Confusion dh Mistake gksrh gSaA Data Flow bl ckr dks
Show djrk gS fd fdlh Organization esa Data dks fdl izdkj ls Handle fd;k tkrk gS]
Data dks dgka Store fd;k tkrk gS vkSj Data ds lkFk D;k Processing dh tkrh gSA
tcfd Data Medal Data dh Internal ckrksa dks rFkk Data ds chp dh vkilh Relationships dks fcuk bl ckr dh ijokg fd, Represent djus dk dke djrk gS] fd Data dks dkSu
Handle dj jgk gS vkSj Data ds lkFk fdl izdkj dh Processing dks Apply fd;k tk jgk
gSA
Data Flows dks lkekU;r;k Data Flow Diagrams(DFD) esa Document fd;k tkrk gSA
mnkgj.k ds fy, vxys fp= esa ge Music Store Organization ds Top Level Data Flow Diagram dks ns[k ldrs gSaA
bl fp= esa ge ns[k ldrs gSa fd ,d Order ysus dh izfØ;k esa nks cMh ckrsa Involved gSaA igyh
Customer dh Information ysuk o nwljh Order fd, tkus okys Items dh Information ysukA bl fp= ds gj Process dks vkSj Explore djds ge Data Flow dh vkSj vf/kd Deep Details izkIr dj ldrs gSa] tSlkfd vxys nks fp=ksa esa n”kkZ;k x;k gSA
bl fLFkfr esa Diagrams fdlh System dh bruh Detailed Information ns nsrs gSa] fd ,d
Application Designer ml Application dks Design djus dk Plan cuk ldrk gSA Data Flow o Data Model nksuksa dks Separate j[kus ds fy, ge dqN Guide Lines dk iz;ksx dj
ldrs gSaA ;s Guide Lines fuEukuqlkj gSa%
1 ,d Data Flow Diagram ;s Show djrk gS fd Data dks dkSu Use ;k Handle dj
jgk gS] tcfd Data Model ,slk ugha djrk gSA
2 ,d Data Flow Diagram ;s Show djrk gS fd Business Related Data dks fdl
rjg ls o fdu ek/;eksa (People Inquiry etc.) ls Collect fd;k x;k gS] tcfd Data Model bl ckr dh tkudkjh ugha nsrk gSA
3 ,d Data Flow Diagram Data ij Perform gksus okys mu Operations dks Show
djrk gS] tks Data dks ,d :i ls nwljs :i esa Transform djrs gSa] tcfd Data Model bl ckr dks Show ugha djrk gSA
,d Data Model esa fdlh Database esa Store gksus okys Data tSls fd Entities, Attributes o Entity Relationships dh tkudkjh gksrh gSA ;fn fdlh Entity ds Data dks fdlh
Database esa Store ugha fd;k tk jgk gks] rks og Entity ml Database dk fgLlk ugha gksrk
gSA
mnkgj.k ds fy, gkykafd Music Store dk Data Flow Diagram Music Store ds ml
Employee dks Show djrk gS] tks Music Store ds fofHkUu izdkj ds Data dks Handle djrk
gS] ysfdu ml Employee ls lEcaf/kr fdlh izdkj ds Data dks Database esa Store ugha fd;k
tk jgk gSA blfy, Music Store Database ds ER Diagram esa Employee uke dk dksbZ
Handle djrk gSA dsoy dksbZ cgqr gh cMk DBMS gesa ;s lqfo/kk nsrk gS fd ge Physical Schema dks Control dj ldsaA
bl rjhds dk lcls cMk Qk;nk ;s gS fd Database Design djus okys o mls Use djus okys]
nksuksa dks gh ;s tkuus dh t:jr ugha gksrh gS fd Data Physically fdl izdkj ls Store gks jgk gSA bl rjhds ds dkj.k Database dks Access djuk dkQh ljy gks tkrk gS D;ksafd ge cgqr
gh vklkuh ls Logical o Physical Schemas dks Change dj ldrs gSaA
pwafd ge ,d Database dks rhu rjhdksa ls ns[k ldrs gSa] igyk Logical Schema ds :i esa]
nwljk User ds :i esa o rhljk Physical Schema ds :i esa] blfy, vktdy dqN
Database dks Three-Schema Architecture Hkh dgk tkus yxk gSA System Programmers o vU; yksx tks fd Physical Storage dks Manage djrs gSa] os okLro esa Physical Schema ds lkFk Deal djrs gSaA vkt gekjs lkeus ftrus Hkh DBMS Softwares gSa] os gesa ml DBMS esa
Store gksus okys Data ds File Structure dks Control djus dh dksbZ lqfo/kk iznku ugha djrs
gSaA
Database Designers, Database Administrators o dqN Application Programmers Logical Schema dks Use djrs gSaA End User Interactively dke djrs gSa] ;kuh igys ls cus
gq, Database System dks Application ds ek/;e ls Use djrs gSa tcfd Application Programmers Database dks User View ds vk/kkj ij ns[krs gSa vkSj End User ds fy,
Database Applications Create djrs gSaA
tc ge ,d ckj ER Diagram Complete dj ysrs gSa] mlds ckn Create gksus okys
Conceptual Logical Schema dks Use fd, tkus okys DBMS ds vk/kkj ij Formal Data
igyh utj esa ;s Relation ,d Flat File ;k fdlh Spreadsheet ds Rectangular Portion dh rjg gh fn[kkbZ nsrk gSA ysfdu tc ge bl Table dks Set Theory ds vk/kkj ij ,d
Relation ds :i esa ns[krs gSa] rc bl Relation ds dqN cgqr gh Specific Characteristics gesa fn[kkbZ nsrs gSaA Set Theory ds vk/kkj ij ns[kus ij bl Relation dk gj Column DBMS esa
Store fd, tkus okys Constraints dks Represent djrk gSA
tc ge Set Theory ds vk/kkj ij fdlh Relation ds ,d Column dh Characteristics dks
dks Application dh Processing ds nkSjku Generate gksus okys Intermediate Query Result dks Database esa Store djus ds ctk; bu Virtual Tables esa Store djds Main Memory esa Store djus dh lqfo/kk nsrs gSa] ftlls Query dh Performance vPNh gks tkrh gS] D;ksafd
Main Memory dh Speed gesa”kk gh Disk dh Speed ls T;knk gksrh gSA
DBMS dk nwljk Qk;nk ;s gksrk gS fd tks Tables Relational Data Model ds Rules dks
Violate djrs gSa] DBMS mUgsa Virtual Tables ds :i esa Main Memory esa Store djds
Manage djrk gS] ftlls Actual Database esa Stored Data dh lqj{kk dks fdlh izdkj dk
ldrk ;k fdlh Primary Key Field esa NULL Store ugha fd;k tk ldrk gSA Null ,d
Special Database eku gksrk gS] ftldk eryc “Unknown” gksrk gSA
;fn gekjs Relation esa dsoy ,d gh Record gks vkSj ge Primary Key Filed dks Null dj nsa]
rks dksbZ Problem Generate ugha gksrh gS] ysfdu tSls gh ge ml Relation esa nwljk Record Enter djsaxs] ge Primary Key Fields ds Uniqueness dh Property dks [kks nsaxsA blfy, ge
dHkh Hkh fdlh Table ds Primary Key Field dks Null Assign ugha dj ldrs gSaA
bl Constraint dks Entity Integrity dgk tkrk gS vkSj Database esa ftruh ckj Hkh Data Enter ;k Modify fd;k tkrk gS] DBMS Primary Key dks Enforce djds Database ij Apply djrk gS] ftlls gj Record gesa”kk Unique cuk jgrk gSA
ge fdlh Primary Key Field esa Duplicate Data Store ugha dj ldrs gSaA ;fn ge ,slk djus
Define fd;k tkrk gSA bl Table esa ;s Composite Key gj Row dks Uniquely Identify djus ds lkFk gh Order Lines, Orders o Items ds chp dh Relationship dks Hkh
Represent djrk gSA
Order Lines Relation esa ItemID Column mlh rjg dk Primary Key gS] ftl rjg dk
Item Table ij gSA ;s Primary Key nks Tables ds chp One To Many dh Relationship dks Represent djrk gSA
blh rjg ls Orders o Order Lines ds chp Hkh ,d One To Many dh Relationship gS] D;ksafd Order Lines Table dk OrderID mlh rjg dk Primary Key gS] ftl rjg dk
Orders Table esa gSA
tc fdlh Table esa oSlk gh Primary Key gksrk gS] tSlk fdlh nwljh Table esa gksrk gS] rks bl
ysfdu gekjs Music Store Database esa ;fn ge CustID Foreign Key dks Null Assign djrs
gSa] rks xEHkhj leL;k,a iSnk gks ldrh gSa] D;ksafd ;fn Orders Table esa CustID Foreign Key dks Null Assign fd;k tkrk gS] rks ;s irk yxkus dk dksbZ rjhdk ugha cprk gS] fd ml Order dks fdl Customer us Place fd;k gSA
Primary Keys o Foreign Keys dh Matching ds vk/kkj ij gh ,d Relational DBMS
fofHkUu izdkj dh Relationships dks Represent djrk gSA mnkgj.k ds fy, ekuyks fd Music Store dk dksbZ Employee ;s tkuuk pkgrk gS fd Order Number #600000 ij fdl Title dk Order fd;k x;k gSA
bl fLFkfr esa DBMS Line Items Table esa lcls igys mu Rows dks Identify djrk gS]
ftuesa Order Number #600000 Stored gSA fQj DBMS mu Identified Rows esa ls Item Numbers dks Select djrk gS vkSj mUgsa Items Table ds Item Numbers ls Match djrk
gSA ftl Row esa nksuksa Item Numbers Match gksrs gSa] DBMS ml Row ls Associated Title dks Retrieve dj ysrk gSA
Referential Integrity
fiNys Paragraph esa Data ds Access gksus dk tks rjhdk crk;k x;k gS] og rjhdk rc rd
vPNs rjhds ls dke djrk gS] tc rd fdlh dkj.ko”k dksbZ ,slk Record Orders Table esa ugha gksrk gS] ftlesa OrderID Filed esa Null gksA D;ksafd ;fn Order Table esa OrderID Field esa Null Stored gks] rks ml Row ls Match gksus okyk dksbZ Record Order Lines Table esa izkIr ugha gksxkA
Database Schema o Database dh Base Tables ds lkFk Directly dke dj ldrs gSaA
ysfdu tks End Users gksrs gSa] mUgsa Application Programs ;k Database Schema ds ckjs esa
iwjh tkudkjh ugha gksrh gS] blfy, lkekU;r;k bUgsa Database dh Base Tables dks Directly Use djus ls jksdk tkrk gSA
pwafd End User dks dHkh Hkh Database Schema o Application Program ds ckjs esa iwjh
tkudkjh ugha gksrh gS] blfy, ;fn os Database dh Base Tables ds lkFk Directly dke
djrs gSa] rks gks ldrk gS fd os vius Database dh Tables esa Stored Data dks xyrh ls
Corrupt dj nsaA blfy, Data dh lqj{kk ds fy, End Users dks Database dh Base Tables ds lkFk Directly dke djus dk vf/kdkj Database Developer }kjk ugha gksrk gSA
blfy, Relational Data Model ,d ,slk rjhdk Provide djrk gS] ftlesa gj User dks
Database esa mldk Lo;a dk ,d Window feyrk gS vkSj gj End User mlh Window esa
viuk dke djrk gSA ;s Window Database Design dh lHkh Details dks User ds fy, Hide dj nsrk gS] ftlls ,d End User dHkh Hkh Database dh Base Tables dks Direct Access ugha dj ikrk gS vkSj Database dk Data End User dh xyrh ls Damage gksus ls gesa”kk
cpk jgrk gSA
View Hkh ,d rjg dk Table gh gksrk gS] ysfdu ;s Data ds lkFk Database esa Store ugha gksrk gSA cfYd ;s ,d uke ds lkFk Data Dictionary esa Store gksrk gSA blesa gesa”kk dksbZ
Database Query gksrh gS] ftlds vk/kkj ij dksbZ View Database ls viuk Data Retrieve djrk gSA ,d View esa ,d ls T;knk Tables, Rows o Columns ds Data gks ldrs gSaA
Views dks bl rjhds ls Store djus dk lcls cMk Qk;nk ;s gS fd tc Hkh User fdlh Data Manipulation Language (SQL Statement) esa View dk uke Include djrk gS] rc DBMS
ml View Name ls Associated Query dks Execute djrk gS vkSj View ds Table dks fQj
ls Recreate djrk gSA bldk eryc ;s gS fd View esa gesa”kk Current Data gh gksrk gSA
,d View Table Main Memory esa rHkh rd miyC/k jgrk gS] tc rd dksbZ Data Manipulation Language (SQL Statement) Execute gksrk gSA tSls gh User nwljk SQL Statement Use djds nwljh Query Create djrk gS] fiNyh Query dh View Table Main Memory ls Remove gks tkrh gS vkSj Generate gksus okyk u;k Result View esa Stored ml
fiNyh Query ds Result dks Replace dj nsrk gSA blfy, ,d View Table gesa”kk ,d
Virtual Table gksrh gSA
dqN DBMS ;s lqfo/kk nsrs gSa fd View Table ds Contents dks Base Table dh rjg Store fd;k tk ldrk gSA ysfdu fdlh View Table dks Base Table cukus dk dksbZ fo”ks’k Views dks bl rjhds ls Store djus dk lcls cMk Qk;nk ;s gS fd tc Hkh User fdlh Data Manipulation Language (SQL Statement) esa View dk uke Include djrk gS] rc DBMS
ml View Name ls Associated Query dks Execute djrk gS vkSj View ds Table dks fQj
ls Recreate djrk gSA bldk eryc ;s gS fd View esa gesa”kk Current Data gh gksrk gSA
,d vkSfpR; ugha gksrk gS] D;ksfd ,sls DBMS Softwares esa Hkh fdlh View Table ls Create dh xbZ Base Table dks ml fLFkfr esa Automatically Update djus dh lqfo/kk ugha gksrh gS]
tc ml Table esa Change fd;k tkrk gS] ftlds vk/kkj ij View Table dks cuk;k x;k FkkA
;kuh ;fn fdlh Table X ls ,d View Table Y dks Create fd;k tkrk gS vkSj bl View Table dks Base Table ds :i esa Database esa Store dj fy;k tkrk gS vkSj mlds ckn
Table X esa dksbZ ifjorZu fd;k tkrk gS] rks bl View Table Y ls Create gksus okyh Base Table Y esa dksbZ Automatic Updation ugha gksrk gSA
blfy, tSls gh ge Base Table X esa dksbZ ifjorZu djrs gSa] Base Table Y ds Data gekjs Database ds fy, Out Of Date gks tkrs gSa] ftudk gekjs Database ds fy, dksbZ Meaning ugha jg tkrk gSA
vc ,d loky fnekx esa vk ldrk gS fd tc Data dks Store djus ds fy, ,d Base Table Create fd;k gh tkrk gS] rks Views dks Use djus dh D;k t:jr gSA rks Views dks Use djus ds rhu vPNs dkj.k gSa%
le; Create o Destroy fd;k tk ldrk gSA pwafd Views esa fdlh izdkj dk Stored Data ugha gksrk gS] cfYd fdlh ,slh Query dk Specification gksrk gS] ftlds vk/kkj ij Virtual Table Create gksrh gS] blfy, Views dks Add djus ;k Delete djus ij bldk Database dh Base Tables o Tables esa Stored Data ij dksbZ izHkko ugha iMrk gSA
fdlh View dks Remove djus ij dsoy rHkh leL;k iSnk gks ldrh gS] tc ml View dks
fdlh Application Program esa Use fd;k x;k gks vkSj Program dks bl izdkj ls Modify uk fd;k x;k gks fd og ml View ds fcuk Hkh fdlh vU; View ;k Base Table ds vk/kkj ij
Bhd rjhds ls dke dj ldsA
Data Dictionary
gj DBMS esa ,d Data Dictionary ;k Catalog gksrk gSA Relational Database dk
Structure blh Catalog ;k Data Dictionary esa Store gksrk gSA Data Dictionary Relations ds lewg ls cuh gksrh gS vkSj gekjs Database ds lHkh Elements bl Data Dictionary Relation esa mlh rjg ls Store gksrs gSa] ftl rjg ls ,d Entity ds Relation esa fofHkUu Data Store gksrs gSaA ;kuh Data Dictionary Relation esa Database ds lHkh Relations Data dh
rjg Store gksrs gSaA
ge Data Dictionary Relation dh Hkh mUgha Tools dk iz;ksx djds Query dj ldrs gSa] ftu
Tools dk iz;ksx djds fdlh lkekU; Relation dh Query djrs gSaA dksbZ Hkh User Data Dictionary Tables dks Directly Modify ugha dj ldrk gSA
fQj Hkh ftu Data Manipulation Language Commands (SQL Commands) dk iz;ksx ge
Database ds Elements dks Create o Destroy djus ds fy, djrs gSa] mUgha Commands dk iz;ksx ge Data Dictionary Tables ds Rows dks Modify djus ds fy, Hkh dj ldrs gSaA
gesa Data Dictionary esa fuEu izdkj dh Information izkIr gksrh gSa%
1 gj Table dks Create djus okys Columns dh Definitions dh Information 2 Relations ij Apply fd, x, Integrity Constraints dh Information 3 Security Information tks ;s crkrh gS fd dkSulk User fdl Table ij fdl izdkj ds
Operations dks Perform dj ldrk gSA 4 Database Structure Elements tSls fd View o vU; User Defined Domains dh
Information
User tc Hkh fdlh Hkh rjhds ls Data dks Access djus dh dksf”k”k djrk gS] Relational DBMS lcls igys Data Dictionary esa ;s r; djus ds fy, tkrk gS fd User us ftl
Database Elements dh Request dh gS] D;k okLro esa os Elements Database Schema dk fgLlk gSa vFkok ughaA lkFk gh DBMS ;s Hkh Verify djrk gS fd D;k User dks ml tkudkjh
tc User Database ds fdlh Data dks Modify djuk pkgrk gS] rc Hkh DBMS Data Dictionary esa tkrk gS vkSj mu Integrity Constraints dks Check djrk gS] ftUgsa mu
Relation ij Place fd;k x;k gks ldrk gSA ;fn DBMS dk Data ds lkFk Constraint Match gks tkrk gS] vkSj DBMS dks yxrk gS fd User ,d Legal Operation dj jgk gS] rks
DBMS ml User dh Request dks iwjk djrk gS vkSj Database ds fdlh Relation ds Data dks Modify djus dh Permission ns nsrk gSA
ysfdu ;fn User Data ds lkFk Apply fd, x, Constraint dh t:jr dks iwjk ugha djrk gS]
Relations ij Apply djds Design dks Check djrs gSaA
Translating an ER Diagram into Relations
,d ,slk ER Diagram, ftlds lHkh Many To Many Relationships dks Composite Entities dk iz;ksx djds One To Many Relationships esa Convert dj fy;k x;k gks] rks
Directly Database Relations esa Translate dj ldrs gSaA ,slk djus ds fy, gesa fuEu Steps dks Follow djus gksrs gSa%
1 gj Entity ds fy, ,d Table Create djrs gSaA
2 gj og Entity tks fdlh ,d ;k ,d ls T;knk Relationships ds dsoy “One” End dh
rjQ gks vkSj “Many” End dh rjQ uk gks] ,sls Entity dh Table esa dsoy ,d
tSlkfd ge fiNys fp= esa ns[kdj le> ldrs gSa] fdlh Hkh Design dh 6 Normal Forms gks ldrh gSaA ;s fp= bl ckr dks n”kkZrk gS fd ;fn dksbZ Design fdlh Higher Form esa gS rks og
Design mldh lHkh Inner Normal Form esa t:j gksrk gSA ;kuh ;fn dksbZ Design Inner Normal Form esa ugha gks rks mls Higher Normal Form esa Define ugha fd;k tk ldrk gSA
T;knkrj Cases esa ;fn ge gekjs Relations ;k Tables Third Normal Form (3NF) rd Hkh
Normalize dj ysrs gSa] rks ge [kjkc Database Design ds T;knkrj Problems dks Solve dj pqds gksrs gSaA ;kuh fdlh Database dh lHkh Tables dks 3rd Normal Form rd
Normalize dj ysus ij ml Database dh Design lEcaf/kr T;knkrj ijs”kkfu;ka lekIr gks
tkrh gSaA
Boyce-Codd (BCNF) o 4th Normal Form dks fo”ks’k Situations dks Handle djus ds fy,
dHkh&dHkkj gh Database ij Apply fd;k tkrk gSA gkykafd bu nksuksa Normalization Processes dks Hkh Conceptually le>uk ljy gksrk gS vkSj t:jr iMus ij bUgsa Practice esa Hkh fy;k tk ldrk gSA
Fifth Normal Form ds fu;e cgqr gh Complex gksrs gSa vkSj bUgsa Practically Use djuk
dkQh eqf”dy gksrk gSA dksbZ Relation 5th Normal Form esa gS ;k ugha] bl ckr dks Verify djuk dkQh eqf”dy gksrk gSA T;knkrj Database Designers 5th Normal Form rd fdlh Hkh
Relation dks Normalize ugha djrs gSaA ;fn mUgsa yxrk gS fd mudk Relation 3rd Normal Form ;k t:jr ds vk/kkj ij 4th Normal Form esa gS] rks os ;s eku ysrs gSa fd mudk Design Generally Problem Free gSA
fp= esa n”kkZ, x, 6 Normal Forms ds vykok ,d vkSj Normal Form gksrk gS] ftls
Domain/Key Normal Form dgk tkrk gSA ;s ,d iwjh rjg ls Theoretical Concept gksrk gS vkSj vkt ds le; esa bl Normal Form dks fdlh Hkh Practical Design esa Use ugha fd;k
tkrk gSA
First Normal Form
;fn fdlh Table ds lkjs Data ,d 2-Dimensional Table ds :i esa gSa vkSj muesa ls fdlh Hkh
Data ds Group dk Repetition ugha gks jgk gS] rks ml Table dks 1st Normal Form esa ekuk
ldrs gSA
1st Normal Form dks le>us dk eq[; vk/kkj ;s gS fd ge Data ds Repeating Group dh
izd`fr dks le>saA fdlh Relation dk ,d ,slk Attribute, ftlesa ,d ls T;knk Data Store gks ldrs gksa] dks Repeating Group Data dgk tkrk gSA tc ge fdlh Repeating Group Data dks ER Diagram esa Represent djuk pkgrs gSa] rc ge ml Repeating Group Data dks Multi-Valued Attribute ds :i esa Represent djrs gSaA
mnkgj.k ds fy, ekuyks fd ge fdlh Employee ds Relation ds lkFk izfØ;k dj jgs gSa vkSj
gesa fdlh Employee ds cPpksa ds uke o Birth Date dks Employee ds Relation esa Data ds
Represent djus okys ,d gh Row ds Child Name Filed o Child Birth Date Field esa ,d ls T;knk ekuksa dks Store djus dh t:jr iM ldrh gS] tcfd fdlh Hkh Relational Database esa fdlh ,d Row ds ,d Field esa dsoy ,d gh eku dks Store fd;k tk ldrk
gSA
bl fLFkfr esa Child dk uke o Birth Date Employee ds Record esa ,d ls T;knk ckj
Repeat gks ldrs gSa] blfy, bu nksuksa Data dks Employee ds Relation ds fy, Repeating Group of Data dgk tk ldrk gSA bl ckr dks ge ,d lkj.kh }kjk fuEukuqlkj n”kkZ ldrs gSa%
bl Table esa ge ns[k ldrs gSa fd Rahul uke ds ,d Employee ds nks cPps Rohit o Mohit gSa] ysfdu ge nksuksa cPpksa ds Data dks Employee ds Relation esa Store ugha dj ldrs gSa]
D;ksafd ;fn ge ,slk djus dh dksf”k”k djrs gSa] rks gesa ,d gh Attribute Column esa ,d ls
T;knk ukeksa o Birthdates dks Store djuk gksxk] tks fd ,d Relational Database esa lEHko
ugha gSA
fdlh Relational Database esa Repeating Groups dks Allow uk djus dk ,d vPNk dkj.k
Hkh gSA bl dkj.k dks le>us ds fy, ge ,d mnkgj.k ns[krs gSa] ftlesa ,d Table esa fuEukuqlkj
dqN Employees o muds cPpksa ds uke Stored gSa%
bl Table esa ge ns[k ldrs gSa fd ,d gh Single Row ds Children Name Field o Children Birthdates Field nksuksa gh Fields esa ,d ls T;knk eku Stored gSaA ;s O;oLFkk nks cMh Problems Create djrh gS%
Verify gks lds fd geus ftl cPps dk uke igys fy[kk gS] ge mlh cPps dh Date Of Birth Hkh igys gh fy[k jgs gSa ;k ughaA
2 tc ge fdlh Table esa Multi-Valued Data Store djrs gSa] rc DBMS fdlh Data dks Search djus ds fy, ml Multi-Valued Column dks Extract djrk gS vkSj ml
Column ij Sequential Processing dks Apply djds Required Data dks izkIr
djrk gS] tks fd lcls /kheh Searching Process gksrh gSA
bu nksuksa leL;kvksa dk ,d gh Solution gS fd fdlh Hkh Single Column esa Multiple Values dks Store uk fd;k tk, ;kuh Repeating Group of Data dks fdlh Hkh Relation esa Avoid fd;k tk,A Repeating Groups dh leL;k ls cpus vkSj Relation dks First Normal Form esa
Repeating Group ds Data dh fofHkUu Values dks Handle djus ds fy, Relation esa Columns dh la[;k dks Increase dj fy;k tkrk gS%
bl Example esa fdlh Employee ds rhu Childs ds uke o Birth Dates dks Store fd;k tk
ldrk gSA ;s Table First Normal Form ds Criteria ls esy ugha dj jgk gSA gkykafd bl
Table esa Data ds Repeating Groups ugha gSa vkSj gj Child dh Birth Date dks vyx
Store fd;k x;k gSA fQj Hkh bl Design esa dbZ Problems gSa] tks fuEukuqlkj gSa%
1 bl Relation esa ge flQZ rhu Child ds gh Name o Birth Date dks Store dj
ldrs gSaA blfy, ;fn ge Jane Smith ds pkSFks cPps dk uke o Date Of Birth Store djuk pkgsa] rks bl Relation esa ml Child ds fy, dksbZ txg ugha gSA ;fn ge pkSFks
cPps dk Hkh Data blh Relation esa Store djuk pkgsa] rks ;k rks gesa ,d vkSj Field Pair Create djuk gksxk ;k fQj ,d vkSj Row esa bl Data dks Store djuk gksxkA
;fn ge pkSFks cPps ds Data dks ,d vkSj Row esa Store djrs gSa] rks fQj ml cPps dks
mlds Father ds EmpID ls Relate djus ds fy, gesa EmpID ds lkFk de ls de
Group ds Multiple Records ;k Instances dks Handle dj ldsA ;fn ge gekjs bl
mnkgj.k ds lUnHkZ esa ns[ksa] rks gesa Children uke dh ,d vkSj Table dks Create djuk gksxk]
ftlesa fuEukuqlkj Data Store fd, tk ldrs gSa%
Employees EmpID FirstName LastName
1001 Jane Doe 1002 John Doe 1003 Jane Smith 1004 John Smith 1005 Jane Jones
Employees EmpID ChildName BirthDate 1001 Mary 1/1/92 1001 Sam 5/15/94 1002 Mary 1/1/92 1002 Sam 5/15/94 1003 John 10/5/94 1003 Pat 10/12/90 1003 Lee 6/6/96 1003 Mary 8/21/94 1004 Michael 7/4/96 1005 Edward 10/21/95 1005 Martha 10/15/89
ge ns[k ldrs gSa fd vc nksuksa gh Tables esa dksbZ Hkh Repeating Group Of Data ugha gS blfy, bl Design ls igys crkbZ xbZ lHkh izdkj dh leL;k,a lekIr gks tkrh gSaA ;kuh bl
gkykafd First Normal Form ds Relations esa Data ds Repeating Groups ugha gksrs gSa] ysfdu muesa vU; izdkj dh dbZ vkSj Problems gksrh gSaA First Normal Form ds Relation dh
leL;kvksa dks le>us ds fy, ge Music Store Database ds Data Entry Form ls
Connected Back-End Table dks gh mnkgj.k ds :i esa ys jgs gSa] ftlesa Data Entry Form
ls Enter fd;k x;k Data tkdj Store gksrk gSA Music Store Data Entry Form ls
Connected Back-End Relation ds Notation dks ge fuEukuqlkj Represent dj ldrs gSa%
bl mnkgj.k esa ge OrderID o ItemID nksuksa ds Combination dks Primary Key ds :i esa
Use dj ldrs gSaA ;fn ge OrderID o ItemID ds Combination dks Primary Key ds :i
esa Use djrs gSa] rks bl Relation esa ge nks cgqr gh egRoiw.kZ dkeksa dks iwjk ugha dj ldrs gSa]
ftUgsa fuEukuqlkj crk;k x;k gS%
1 ge rc rd fdlh Customer ds Data dks Relation esa Store ugha dj ldrs gSa] tc
rd fd og Customer de ls de ,d Order Place uk djs] D;ksafd fcuk ,d Order vkSj ml Order ij fLFkr ,d Item ds] gekjs ikl ,d Complete Primary Key ugha gksrh gSA
2 blh rjg ls ge rc rd fdlh Item dh Information dks Hkh Relation esa Store ugha dj ldrs gSa] tc rd fd dksbZ Customer fdlh Order }kjk ml Item dks Order uk djs] D;ksafd fcuk OrderID ds Hkh ,d Complete Primary Key ugha cu ldrkA
dksbZ Hkh Relation, tks fd First Normal Form esa gksrk gS] mlesa Insertion Anomalies dh
fLFkfr Common :i ls gksrh gh gSA Insertion Anomalies dh fLFkfr rc iSnk gksrh gS] tc
fdlh ,d Relation esa ,d ls T;knk Entities ds Data dks Store djus dh dksf”k”k dh tkrh
gSA bl Situation esa Anomaly gesa ml le; ,d Unrelated Entity tSls fd Item ds Data dks Insert djus ds fy, etcwj djrk gS] tc ge fdlh nwljs Entity tSls fd Customer ds
Data dks Insert dj jgs gksrs gSaA
First Normal Form ds Relations ml le; Hkh leL;k,a iSnk djrs gSa] tc ge ml Relation ls fdlh Data dks Delete djus dh dksf”k”k djrs gSaA mnkgj.k ds fy, ekuyks fd ge ml
Customer ds Order dks Delete djuk pkgrs gSa] ftlus vius Single Item dk Order Cancel dj fn;k gSA vc ;fn
1 Customer us igyh gh ckj Order fn;k gks vkSj dsoy ,d gh Item dk Order fn;k gks] rks ml Customer ds Order dks Delete djus ij ml Customer dh
Information Hkh Music Store ds Database ls Permanently Delete gks tk,xh]
ftlls Music Store Organization dk ml Customer ls rc rd ds fy,
Permanently Link VwV tk,xk] tc rd fd og nqckjk dksbZ Order ugha nsrk gSA
2 Customer us igyh gh ckj ml Item dk Order fn;k gks vkSj ml Customer ls
igys fdlh nwljs Customer us ml Item dk Order ugha fn;k gks] rks ml Order dks
Delete djus ij ml Item dh Information Hkh Music Store ds Database ls
Permanently Delete gks tk,xhA
3 Customer us vius Order esa dsoy ,d gh Item dk Order fn;k gks] rks Order dks
Delete djus ij ml Order dh iwjh Information Database ls Delete gks tk,xhA
Orders Relation esa gj Order ds lkFk gj Customer dh Information dks ckj&ckj Store djus dh otg ls Music Store Database esa ,d gh Customer ds cgqr lkjs Unnecessary Duplicated Data Store gks tkrs gSaA
blfy, tc ,d Customer Move gksrk gS] rc ml Customer us ftrus Hkh Items ds ftrus
Hkh Orders Music Store Organization dks fn, gksrs gSa] Database esa mu lHkh Items ds
Second Normal Form First Normal Form dh fofHkUu Anomalies dks gVkus dk lek/kku ;s gS fd First Normal Form okyh Relation ls lHkh Entities dks ,d vyx Relation ds :i esa Define fd;k tk,A
mnkgj.k ds fy, Music Store ds bl Orders Relation esa ls ge pkj Lora= Entities (Customers, Items, Orders o Line Items ) dks vyx dj ldrs gSaA ,slk djus ij
Music Store Organization dk ;s Relation Second Normal Form esa vk tkrk gSA
Theoretical “kCnksa esa Second Normal Form dks fuEukuqlkj ifjHkkf’kr fd;k tk ldrk gS%
tc Relation First Normal Form esa gks vkSj lHkh Non-Key Attributes, Functionally flQZ
Primary Key ij Depend uk gksdj fdlh Non-Key Attribute ij Depend gks] rks ml
Non-Key Attribute vkSj ml ij Depend lHkh vU; Non-Key Attributes dks ml Relation ls gVkdj ,d u, Relation esa Define djuk pkfg, vkSj bl u, Relation esa ml Key dks
fdlh Hkh le; gj Attribute esa dsoy ,d gh eku gksrk gSA bl fLFkfr esa ge dg ldrs gSa fd
First Name, Last Name, Street Address, City State, Pincode o Telephone Numbers ;s lHkh Functionally Customer Number ij Dependent gSaA Attributes ds chp dh bl
bl fLFkfr esa gj Determinant Relation dk Primary Key cu tkrk gS vkSj ftrus Hkh
Attributes bl Determinant ij Depend gksrs gSa] os lHkh Attributes Relation ds Non-Key Attributes cu tkrs gSaA bl Concept ds vk/kkj ij Music Store Organization ds
Original Relation esa ls ftu pkj Entities dks Lora= :i ls Identify djds vyx fd;k tkrk
ls Check djrs gSaA ge Design Process ds fdlh Hkh Stage esa Function Dependency vkSj@;k Entities dks ns[k ldrs gSa vkSj ,d nwljs ds Against Check dj ldrs gSaA
D;ksafd gesa”kk ;s t:jh ugha gksrk gS fd geus ftl Relation dks First Normal Form esa eku
fy;k gS] og okLro esa First Normal Form esa gksA Design Process ds fdlh Hkh Stage esa gesa ,slk eglwl gks ldrk gS] fd Relation iwjh rjg ls First Normal Form esa ugha gS vkSj mls
fQj ls First Normal Form esa ykus dh t:jr gSA tc ge Relation ij Second Normal Form ds Criteria Rules dks Apply djrs gSa] rc Original Relation esa Present Anomalies Eliminate gks tkrh gSa vkSj ge fuEu dke dj ldrs gSa%
1 Customer ds Order Place djus ls igys gh ge ml Customer ds Data dks
Database Relation esa Store dj ldrs gSaA
2 ge fdlh Order ds Data dks fcuk Items dh Information ds Hkh Database Relation esa Store dj ldrs gSaA
3 fdlh Customer }kjk fdlh Particular Item dk Order fn, tkus ls igys Hkh ge
Item ds Data dks Database Relation esa Store dj ldrs gSaA
Third Normal Form dk Theoretical Definition ;s gS fd dksbZ Relation rc Third Normal Form esa gksrk gS] tc ml Relation esa dksbZ Transitive Dependencies ugha gksrh gSaA
Original Relation esa geus ftl Functional Dependencies ds ckjs esa tkuk Fkk] mls gh
;gh Dependency Original Items Relation esa gSA Warehouse ds Phone Number dk
Functionally Item Number ij Depend gksus dk Only dkj.k ;gh gS fd Distributor Functionally Item Number ij Dependent gS vkSj Phone Number Functionally Distributor ij Dependent gSA blfy, okLrfod Functional Dependency fuEukuqlkj gS%
ItemID og Number gS] ftls Music Store Organization vius gj Item dks Uniquely Identify djus ds fy, Use djrk gS] tcfd UPC Code og Industry-Wide Code gS] ftls
gj Item dks Uniquely Identify djus ds fy, Use fd;k tkrk gSA vc bl Relation esa Functional Dependencies fuEukuqlkj gSa%
fd Relation ds fy, Primary Key ugha gksrk gS og ml Relation dk Candidate Key Hkh ugha gksrk gSA
mnkgj.k ds fy, ge ftl Items Table dks mnkgj.k ds :i esa mi;ksx esa ys jgs gSa] mlesa
Distributor ,d Determinant gS ysfdu og Distributor ml Items Table ds fy,
Candidate Key ugha gSA D;ksafd ,d Distributor ls ,d ls T;knk Items Music Store esa vk
jgs gSaA
tc Second Normal Form ds Relation esa dksbZ Transitive Dependency gksrh gS] rc gesa ml Relation dks nks NksVs&NksVs Relations esa Divide dj ysuk pkfg, vkSj nksuksa Relations esa nksuksa Determinants dks Primary Key cuk ysuk pkfg,A ftl Attributes dks Determinants }kjk Determine fd;k tkrk gS] mu Non-Key Attributes dks muds Determinant ds
Relation esa Specify dj nsuk pkfg,A blls Transitive Dependency Remove gks tkrh gS
vkSj blls Associated Anomalies Hkh Remove gks tkrh gSa] lkFk gh gekjk Relation Third Normal Form esa vk tkrk gSA ;fn fdlh Second Normal Form ds Relation esa dksbZ
Transitive Dependency uk gks] rks og Relation Automatically Third Normal Form esa vk
tkrk gSA
Boyce-Codd Normal Form
T;knkrj Relations ds fy, Third Normal Form rd Normalized Relation ,d vPNk
fQj Hkh ifjfLFkfro”k dbZ ckj Third Normal Form ds Relations esa Hkh FkksMh vyx fdLe dh
Anomalies gksrh gSaA
bu Anomalies dks BCNF o Forth Normal Form ds Normalization ds vk/kkj ij
Handle fd;k tkrk gSA ;fn gekjk Relation Third Normal Form esa gks vkSj mlesa dksbZ Extra Ordinary izdkj dh leL;k uk gks] rks gekjk Relation Automatically BCNF o Fourth Normal Form esa gksrk gSA BCNF dh izfØ;k dks le>us ds fy, ge ,d mnkgj.k ys jgs gSaA
ekuyks fd Music Store Organization ;s r; djrk gS fd og vius Database esa ,d vkSj
Relation Add djsxk] ftls og vius Music Store ds Employee ds dke djus ds le; dks
Schedule djus ds fy, Use djsxkA
gj Employee gj jkst 4-Hours dh ,d ;k nks Shift esa dke djsxk vkSj gj Shift esa ,d
Employee dks Music Store ds fdlh ,d Station ¼;kuh Stock Room esa Stock dks
fn, x, Business Rule ds fglkc ls ,d Employee ,d Shift esa ,d Station ij dke
djsxk] blfy, bl Relation esa nks lEHkkfor Primary Keys EmpID + Date + Shift ;k Date + Shift + Station gks ldrh gSaA bl fLFkfr esa Functional Dependency dk Relation fuEukuqlkj cusxk%
EmpID + Date + Shift -> Station, WorkedShift? Date + Shift + Station -> EmpID, WorkedShift?
,d ckr /;ku esa j[ksa fd ;s Functional Dependency Relation mlh fLFkfr esa lgh gSa] tc gj
Station ij gj Shift esa dsoy ,d gh Employee dke djrk gSA ;s Schedule Relation Composite Candidate Keys dks Show dj jgk gSA D;ksafd nksuksa gh Candidate Keys esa Date o Shift Common gSaA Boyce-Codd Normal Form dks fdlh Relation esa Exist blh
rjg dh Characteristics dks Handle djus ds fy, cuk;k x;k gSA BCNF Form esa gksus ds
fy, fdlh Hkh Relation ij bl fu;e dk Apply gksuk t:jh gksrk gS fd Relation Third Normal Form esa gks vkSj Relation ds lHkh Determinants Candidate Keys gksa] rks
fdlh Specify dh xbZ Movie esa ,d ls T;knk Stars gks ldrs gSa vkSj mlh Movie dks ,d ls
T;knk Producers us Produce fd;k gks ldrk gSA Same Stars ,d ls T;knk Movie esa Appear gks ldrs gSa vkSj Producer Hkh ,d ls T;knk Movies esa Involved gks ldrk gSA
blfy, bl Relation ds lHkh Columns dks Composite Primary Key ds :i esa Use djuk
t:jh gks tkrk gSA bl mnkgj.k dks ge fuEu lkj.kh esa ns[k ldrs gSa%
MovieInfo Table
Title Star Producer
Great Film Lovely Lady Money Bags Great Film Handsome Man Money Bags
Great Film Lovely Lady Helen Pursestrings Great Film Handsome Man Helen Pursestrings Boring Movie Lovely Lady Helen Pursestrings
Boring Movie Precocious Child Helen Pursestrings
pwafd bl Relation esa dksbZ Hkh Non-Key Attribute ugha gS] blfy, ;s Relation BCNF Normalization Form esa gSA fQj Hkh ;s Relation fuEu Anomalies Show djrk gS%
1 ge de ls de ,d Producer dks tkus fcuk fdlh Movie ds Stars dks Insert ugha dj ldrs gSaA
2 ge de ls de ,d Star dks tkus fcuk fdlh Movie ds Producer dks Insert ugha dj
ldrs gSaA
3 ;fn ge fdlh Only Producer dh Information dks Delete djrs gSa] rks ge ml
Movie ds Starts dks Hkh Loose dj nsrs gSaA
4 ;fn ge fdlh Movie ls Only Star dks Delete djrs gSa] rks ge ml Movie ds
Producer dh Information dks Hkh Loose dj nsrs gSaA
5 Movie ds gj Star ds fy, Producer ds uke dk Duplication gksrk gSA blh rjg ls
gj Producer ds fy, Movie ds Star ds uke dk Duplication gksrk gSA ;s
bl Relation esa nks Unrelated Entities gSaA igyk Entity Movie o Stars ds chp dh
Relationship dks Handle djrk gS vkSj nwljk Movie o Producer ds chp dh Relationship dks Handle djrk gSA Practically ns[ksa rks ;gh Anomaly dk eq[; dkj.k gS] gkykafd Movie, Star o Producer Entities Hkh Anomaly esa Involved gSaA
fQj Hkh Theoretically tks Anomalies Create gks jgh gSa] os ,d gh Relation esa Multivalued Dependency ds dkj.k Create gks jgh gSa] ftUgsa Forth Normal Form esa Eliminate fd;k
tkrk gSA Forth Normal Form dk fu;e ;s gS fd Relation Boyce-Codd Normal Form esa
gks vkSj mlesa dksbZ Multi-Valued Dependency uk gksA
fdlh Relation esa Multi-Valued Dependency rc Exist gksrh gS] tc fdlh Attribute A dh
gj Value ds fy, fdlh nwljs Attribute B dh cgqr lkjh Values Associated gksa vkSj fdlh
Attribute C dh gj Value ds fy, Attribute A dh cgqr lkjh Values Associated gksa] tcfd
Attribute B o C vkil esa Independent gksaA
ge ftl mnkgj.k dks Use dj jgs gSa] ml mnkgj.k esa bl izdkj dh Dependency gSA D;ksafd
gj Movie Title ds fy, Stars ;k Actors dk ,d Group gS] tks fd Movie ls Associated gSa vkSj gj Movie Title ds fy, Hkh Producers dk ,d Group gS] ftuls Movie Associated gSA fQj Hkh Actors o Producers ,d nwljs ls Independent gSa] D;ksafd buds chp dksbZ Direct Connection ugha gSA bl Multivalued Dependency dks fuEukuqlkj Represent fd;k tk
ldrk gS%
Title ->> Star Title ->> Producer
vkSj bls bl rjg i<k tkrk gS fd%
“Title Multi-Determines Star and Title Multi-Determines Producer.”
Equi – Join blds lcls Common :i esa ,d Join Operation ml le; u, Records ;k Rows Create djrk gS] tc nks Source Tables ds Data vkil esa Match gksrs gSaA D;ksafd ge Rows dks
;fn ge Database ds “kCnksa esa dgsa rks ge dg ldrs gSa fd ge CustID ds vk/kkj ij nks
Tables dks Join dj jgs gSaA Join djus ij gesa izkIr gksus okyh Resultant Table fuEukuqlkj
gksrh gS%
Result Table
CustID FName LName OrderID OrderDate OrderTotal 002 John Doe 001 10/10/99 250.65
002 John Doe 002 2/21/00 125.89 003 Jane Smith 003 11/15/99 1597.99 004 John Smith 004 11/22/99 180,92
004 John Smith 005 12/15/99 565.00 006 John Jones 006 10/8/99 25,00 006 John Jones 007 11/12/99 85.00 006 John Jones 008 12/29/99 109.12
Equi-Join dks ge ,d Table ij Hkh iwjh rjg ls Apply dj ldrs gSaA tc ge Equi-Join djrs gSa] rc Join ,d Source ds gj Row dks nwljh Table ds gj Row ls Compare djrk
gSA First Source Table dh gj Row ds fy, ;s Second Source Table ds Columns esa Matching Data [kkstrk gS vkSj tSls gh dksbZ Matching Row fey tkrk gS] ;s Result Table esa ,d u;k Row Place dj nsrk gSA
ekuyks fd ge First Source ds :i esa Customers Table dks Use dj jgs gSa vkSj Second Source ds :i esa Orders Table dks] rks Result Table fuEukuqlkj Produce gksrh gS%
1 lcls igys CustID 001 ds fy, Orders Search fd;k tkrk gSA pwafd Orders Table esa bl ID ds fy, dksbZ Matching Row ugha gS] blfy, Equi-Join Result Table esa dksbZ Row Place ugha djrk gSA
nks Matching Rows Orders Table esa gSa] blfy, Equi-Join Result Table esa nks Rows Place djrk gS vkSj nksuksa Rows esa nks ckj Same Customer Information dks
Store djds Order dh Information dks Store djrk gSA
bl fp= esa ge Orders Table ds fofHkUu Records dk Relation ,d Index Table ds lkFk
ns[k jgs gSaA ;s Index gesa”kk Sorted Form esa jgrk gS] blfy, bl ij fofHkUu izdkj ds vU;
Operations Perform djds ,d Database fdlh Record dks T;knk Fastly Search dj
ldrk gSA Index esa gj Record ds Keys dh ,d Ordered List gksrh gS] ftlds lkFk Order Table dk gj Record Associated jgrk gSA gkykafd Order Table ds lHkh Records Random Order esa gSa] ysfdu Index Table esa lHkh Records Sorted Order esa gksus dh otg
ls Records dks Fastly Search fd;k tk ldrk gSA
tc ,d ckj ge Index Create dj nsrs gSa] mlds ckn tc Hkh t:jr gksrh gS] rks DBMS dk
Query Optimizer bl Index dk iz;ksx djds gh fdlh Record dks Search djrk gSA gesa bl
Index dks nqckjk Access djus dh rc rd dksbZ t:jr ugha gksrh gS] tc rd fd ge bl
Index dks Delete djuk ugha pkgrs gSaA
tc ge fdlh Table esa dksbZ Primary Key Create djrs gSa] rks DBMS bl Primary Key ;k Composite Key ds Columns ds vk/kkj Lo;a gh ,d Index Create dj ysrk gSA tc Hkh ge
fdlh Table esa dksbZ u;k Record Insert djrs gSa] ml Record ds Primary Key ds eku dks
Uniqueness ds fy, DBMS }kjk Check fd;k tkrk gSA bl Uniqueness ds fy, Directly Base Table ds Primary Key dks Check djus ds ctk; DBMS ml Index dks Check djrk gS vkSj pwafd Index ,d Ordered Form esa gksrk gS] blfy, ;s Verification dkQh rsth
ls gks tkrk gSA
,slk t:jh ugha gksrk gS fd DBMS gesa”kk gekjs Primary Key ds vk/kkj ij gh Index Create djsxkA okLro esa ge Lo;a Hkh gekjh Table ds fdlh Hkh Column ;k Group Of Columns ds
vk/kkj ij Index Create dj ldrs gSaA ysfdu Indexing ds lkFk dqN Trade-Offs Hkh gSa] tks
Clustering Disk ij Data dks Write djuk ;k Disk ls Data dks Read djuk DBMS dk lcls
Slowest dke gksrk gSA ;fn ge Data ds Disk ij Store gksus o Disk ls Data ds Retrieve gksus dh la[;k dks de dj ldsa] rks ge DBMS dh Performance dks c<k ldrs gSaA
Computer esa lHkh Records Disk Page ds :i esa Store gksrs gSaA tc Hkh ge fdlh Record dks izkIr djus dh Request djrs gSa] Database ml Record ds iwjs ,d Page dks Retrieve djrk gS] ftlesa og Record gksrk gSA Page dh Size vyx&vyx Operating Systems ds
vk/kkj ij cnyrh jgrh gSA Page dh Size 512 Bytes ls ysdj 4 KBytes rd gksrh gSA
gesa Disk ls Hkys ,d gh Record dh t:jr D;ksa uk gks] gesa”kk Disk ls lEcaf/kr Record dk
iwjk ,d Page gh Access gksrk gSA blfy, ;fn ge mu Data dks Access dj jgs gSa] tks
leku Disk Page ij Stored gSa ;k tks utnhdh Page esa Stored gSa] rks ge Data Access dh Speed dks c<k ldrs gSaA bl Process dks Clustering dgrs gSa vkSj bldh lqfo/kk
Oracle tSls DBMS esa miyC/k gSA
Cluster dks Primary o Foreign Keys ds Matching ls cuus okys Records dks Hold djus
mu Column ;k Composite Columns ds Same Values dks Share djus okys Records dks Disk ij Physically Store fd;k tkrk gSA bu Records dks ftruk lEHko gksrk gS mruk
utnhd ij Store fd;k tkrk gSA
ifj.kkeLo:i fdlh Table ds fofHkUu Records dbZ Disk Pages ds :i esa fc[kjs gq, jgrs gSa]
ysfdu Matching Primary Keys o Foreign Keys ds Records vDlj Same Page ij gh Store gksrs gSaA Clustering ls lkekU;r;k Join Performance dh Speed c< tkrh gSA fQj
tcfd Vertical Partitioning esa fdlh Table ds Columns dks vkil esa ,d Primary Key }kjk Linked j[krs gq, Split dj fn;k tkrk gSA nksuksa gh Partition Process ds vius dqN
Qk;ns o dqN uqdlku gSaA
Horizontal Partition esa ,d Table dks Records ds vk/kkj ij nks ;k nks ls vf/kd Tables esa Split fd;k tkrk gS] tcfd nksuksa gh Tables dk Structure leku j[kk tkrk gSA Music Store Database esa ge bl rduhd dks Use dj ldrs gSaA
mnkgj.k ds fy, Orders o Line Items Table dks ;fn Horizontal Partitioning ds vk/kkj ij
,d ls T;knk Tables esa Divide djuk gks] rks ge bl dke dks fuEukuqlkj dj ldrs gSa%
OpenOrders (OrderID, CustID, OrderDate) OpenOrderLines (OrderID, ItemID, Quantity, Shipped?) FilledOrders (OrderID, CustID, OrderDate) FilledOrdersLines (OrderID, ItemID, Quantity, Shipped?) tc Hkh OpenOrders Table ds lHkh Items dks Ship dj fn;k tkrk gS] ,d Application Program OpenOrders Table o OpenOrderLines Table ds lHkh Records dks Delete dj nsrk gS vkSj bu Records dks FilledOrders o FilledOrdersLines Table esa Fill dj nsrk
gSA
bl izfØ;k ds dkj.k OpenOrders o OpenOrderLines Table nksuksa esa gh Records dh
la[;k de gh jgrh gS ftlls Data ds Modification o Retrieval dh Performance c< tkrh
gSA gkykafd FilledOrders o FilledOrdersLines Table ls Data ds Retrieval dh Speed dkQh /kheh gksrh gS] ysfdu Music Store bu Tables dks cgqr de ckj Access djrk gSA
bl rjhds ds lkFk rc ijs”kkuh vkrh gS tc Music Store dks Orders Table ;k OrderLines Tables ds lHkh Records dks ,d lkFk Access djus dh t:jr iMrh gSA bl rjhds dks Use djus ij tc ge fdlh Query esa bu nksuksa Tables ds Data dks Access djuk pkgrs gSa] rc
gesa UNION Operator dk iz;ksx djrs gq, nks Queries dks Mix djds Data dks Access djuk iMrk gSA ;fn ge tks Application Create dj jgs gSa] mlesa nksuksa Tables dks cgqr de