AIN102 Microsoft Access Queries

Accelerated Computer Training for Working Professionals Admissions Case

Orange Coast Database Associates Course (800)355-9855 or http://ocdatabases.itgo.com

Orange CoastDatabase Associates

Specializing in Microsoft Office,

Access, SQL, and related technologiesClasses custom designed forWorking Professionals

http://www.dhdursoassociates.com

San Juan Capistrano, CA

(800)355-9855

AIN102 Microsoft Access Queries

Admissions AIN1021

AIN102 – Access Query Design

Introduction to Access Queries forexperienced Windows users

P.O. Box 6142Laguna Niguel, CA 92607949-489-1472http://www.d2associates.com

AdmissionsAIN1022

AIN102 Contact Information

P.O. Box 6142Laguna Niguel, CA 92607949-489-1472http://[email protected]

Copyright 2001-20011 All rights reserved.

AIN102 Notes

This course is based on an earlier course,SQL200A, which was focused on using SQL inthe Access environment. As such thescreenshots still reflect SQL view as well theQuery Designer view. This is actually a plus.

AdmissionsAIN1023

AdmissionsAIN1024

Introduction (s) Facilities Course Packet (May vary by course or class)

– Student questionnaire in front– Collaterals (Map, Catalog, Etc.)– PowerPoint handouts for all sessions– Evaluation form in back– Training Certificate


AdmissionsAIN1025

Orange Coast Database Associates

Loose association of local University instructors and ITProfessionals.

Started in 2004

Training– Open Enrollment (public classes in San Juan Capistrano using

standardized material)

– On-site (custom classes for groups)

– Private desk side training for individuals

Consulting & Programming (incl. offshore)

AdmissionsAIN1026

AdmissionsAIN1027

Quick pace for experienced windows users

Assumes some prior knowledge of Access

End-user, not programmer, oriented

Somewhat structured towards personal use foranalysis and reporting


AdmissionsAIN1028

Select Queries– Filter Criteria

– Calculations

– Joins

– Grouping

Action Queries– Maketable

– Append

– Update

– Delete

Union

Course Topics:


AdmissionsAIN1029

Approach:

SQL View Used in code; but helpful inunderstanding what a querydoes

Query Designer Use to construct queries

Access has many ways to accomplish tasks. Queries can beconstructed using SQL View or the Query Designer. Thiscourse focuses on the latter.


AdmissionsAIN10210

2 Sessions

Lecture

Demo

Extensive student “hands-on”

Exercises are cumulative – laterexamples build on objects createdearlier

Course Format:


AIN102 Resources

Manuals can be downloaded from SlideShare.

Slides can be viewed on SlideShare…

http://www.slideshare.net/OCDatabases

AdmissionsAIN10211

AdmissionsAIN10212

Session 1

– access-qdes-s1-ad.ppt

Session 2

– access-qdes-s2-ad.ppt

Course Schedule (3 hour sessions):


1

AIN102

Access Query Design

Orange Coast Database Associates, Inc.949-489-1472http://www.dhdursoassociates.com

AIN102

Access Query Design

Module 1 – Relational Database Background,Basic Single Table Retrieval Operations

2

AIN102 Module 13 Admissions AIN102 Module 13

AIN102

Session 1 – Review of Relational Databasesand Single Table Retrieval, Functions andOperators

Session 2 – Multi-table retrieval, Subqueries,Unions, Action Queries, Indexes


AIN102

Lecture/discussion with demonstrations

– Mostly practical, but a dose of “theory”

Assumes some familiarity with MS Access

Hands-on

Exercises (Mostly cumulative)

About 3-4 hours per module

Frequent breaks

3


Module 1

Concepts– Relational

databases– SQL– Access Query

Designer

SELECT Query– Basic– Filter criteria– Complex criteria

• Field Operations• Functions

• Operators

• Calculated fields

• Concatenation


Microsoft Access Query Design

Course focus is Microsoft Access Query Design Queries are widely used for:

– Database administration– Enterprise application development– Data driven web sites– Retrieving and modifying data in MS Access databases

A foundation skill for eBusiness and almost all majorbusiness applications that use relational databases

4


Access Query Design and SQL

Class database will be MS Access – the SQLengine Access uses is called JET

A basic knowledge of Access is assumed

Focus of this class will be on the querydesigner, with SQL used from time-to-time toexplain concepts


Relational Database Basics

Storage

Databases

Tables

Rows

Columns

Indexes

Views

SQL interface

5


Storage

In Access one file with extension mdb. I.emydatabase.mdb.

Database splitter can be used to split it intotwo parts – a front end and a back end.

Interface to physical storage via the “JET”database engine. This is the behind-thescenes-workhorse.


Databases

In the Access world refers to all objectsstored in the mdb.– Tables

– Queries

– From

– Reports

– Macros

– Code modules

6


Relational Database Table


Sample Access Database

7


Database Relationships


Approaching Query Design

Try to build queries a step at a time

Save existing queries that are workingas you like; modify them with a newname when building a modified query

Try looking at the generated SQL codefrom time-to-time

8


Query Types

Select Action

– Update– Delete– Insert– Maketable

Special use queries– Data Definition Language (DDL)– Union– SQL pass-through


DDL

Data definition language (DDL) to create andmodify tables, etc.

– Create, alter, drop, etc.

– Must be “hand-coded” in Access

– But can be useful for database administration

Done in MS Access via SQL Specific Queries– Will not be covered in the course

9


MS Access DDL Queries


DCL

Data Control Language (DCL) to control userrights, etc.– Grant

– Revoke

– Constraints

Used primarily in enterprise databases

Can be done in Access but not covered inthis course

10


DML

Data Manipulation Language (DML)– Select Query

– Append Query

– Update Query

– Delete Query

– Maketable Query (a special type of Select)

– Union Query (really combined Selects)

MS Access Query Designer will create thesestatements “behind the scenes”


MS Access Action Queries

11


Other Access Queries

Crosstab

Pass Through – used to pass an SQLstatement directly to a back end databasew/out processing by Access


Sample Database

Before we continue…

Load the sample database if you haven’talready

12

AIN102 Module 123

Query Designer

Admissions AIN102 Module 123

Right click anywherefor SQL View

Double click or dragto add a field

Double click to add atable


SELECT Queries

Basic Syntax:

Select column-list or *

From table-list

* Means all columns

13


MS Access SELECT Query

Drag and Dropor double click


MS Access SELECT SQL

14


Simple Select Query Results


SELECT w/ Where

Filters retrieved rows

Syntax:

SELECT column-list

FROM table-list

WHERE selection-criteria

15


Comparison Operators

< less than

> greater than

<= less than or equal

>= greater than or equal

= equal

<> not equal


SELECT w/ WHERE

16


SELECT w/ WHERE


SELECT w/ WHERE Results

17


Complex Filters

Follows normal boolean logic

Select PatID, LastName, etc…

From patients

Where (LastName = “Thomas” orbirthdate < #1/1/95#) and city =“Corona”)


Complex Filter

AND

18


Select w/ Complex Where


Complex Filter Results

19


Special Operators

LIKE

IN

BETWEEN

IS NULL


Like (“Wild Card Matches”)

Where customer_last_name like “Jo*”– *= string of characters

Where customer_last_name like “Jo?”– ? = exactly one character

Access actually allows more sophisticated Unix stylesearch patterns as well – see help.

20


LIKE

Names ending in “S”


LIKE

Names ending in “S”

21


LIKE Results


IS NULL

Select columnnsFrom clientsWhere zip IS NULL

SQL (including JET) uses three valued logic.Must use IS NULL to test for unknowns. A null isNOT the same as blank or empty.

22


IS NULL


IS NULL

23


IS NULL Results

OK. Now try finding all patients with a blank address. Wasthe above row retrieved? Why or why not?


IN

Select *From patientsWhere lastname IN (“Smith”,“Thomas”, “Juarez”)

Note: what is inside parentheses is a list. Later wewill replace the list with a subquery whichgenerates the list items.

24


IN


IN

List of values

25


SELECT w/in IN Results


BETWEENSELECT *FROM admissionsWHERE admit_date BETWEEN#10/1/2001# and #12/31/2001#

Note: between is inclusive

26


BETWEEN


BETWEEN Results

27


Removing Duplicates

SELECT DISTINCT PatNoFROM admissions

List once each employee who has alabor ticket

Removes duplicate rows from result set


DISTINCT

28


Distinct Results

W/out Distinct With Distinct


Sorting – ORDER BY

DESC will sort in descending order

Basic syntax:

SELECT column listFROM table listWHERE selection criteriaORDER BY column list [DESC]

29



Select *From patientsWhere state in(“CA”, “OR”, “WA”)Order by birthdate desc

Example:List patients in Pacific Coast sortedby youngest to oldest



Note: modify the “select_in” query

30




Sorting – Results

31


Query/SQL Exercises

List all patient numbers, etc. for patients who co-paid more than $20; sort by co-pay amount,largest first

List diagnostics that contain b, d, or q in thediagnostic code

List the patient id’s for admissions in the fall (Sep,Oct, Nov) of 2001 and 2002


Calculated Fields

Example:Select a + b as result

Syntax:SELECT expression AS newcolumn name

Result is a “columnalias”

32


Calculated Fields

New column name

Follow name with “:”


Calculated Fields

33


Calculated Fields - Results


Concatenation

“Adds” two character fields using “&” symbol

Useful for formatting names, addresses, etc.

Example:

– Select firstname & “ “ & lastname as fullname

34


Concatenation

Sort, but don’tshow


Concatenation

35


ConcatenationSingle column with full

name, sorted by last name

Tip: handy for reports


SQL Exercises

List all the patients with a “fullname” field;sorted by last name. Add a calculated fieldwhich shows their loaded copay (copay *1.5).Show the fullname, but not the individualnames.

36


End Session 1

Next session: multi-tableoperations, subqueries, unions,action queries, indexes

1


AIN102

Access Query DesignModule 2

P.O. Box 6142Laguna Niguel, CA 92607949-489-1472http://www.d2associates.com


Module 2

Part 1– Miscellaneous Functions

Strings Dates

– Summaries (Grouping)

Part 2 – Joins,subqueries

– Inner join– Outer joins– Subqueries

Multi-valued Single-valued

• Part 3 – Unions,Action Queries,Indexes• Unions

• Maketable Query

• Delete

• Append

• Update

• Indexes

2


String Manipulation

Trim

Substring

UCase, LCase

Left, Right

See help for others


String Manipulation

3


String Manipulation


String Example

4


Date Functions

Numerous date functions– DatePart– DateDiff– DateAdd– Etc.

Often used:– Year– Month

Ex: where year(birthdate) = 1999


DateDiff How long did patients stay in weeks?

5


DateDiff results

Note: Access has many date functions with many options.


Ex: Date Function – Month()

6


Ex: Date Function – Month()


Result of Month Function

7


Summary Functions

Count

Sum

Min

Max

Avg

Often used in conjunctionwith grouping


Summary Functions in Access

Click the sum symbol

Adds a total row

8


Summary Functions - SyntaxBasic syntax:

SELECT function(column)FROM tableWHERE filter-conditionGROUP BY column-listHAVING group-filter

Group by all columns to left of one(s)you to want aggregate


Simple Column Summaries

This query counts patient admissions In the year 2001

9


Simple Column Summaries


Simple Record Count

10


“The COUNTS”

Count(*) – counts records

Count(fieldname) – counts non–nulloccurrences of field name

Count (distinct fieldname) – counts distinctoccurrences, but not supported in access


Grouping

Organizes results into summary rows, one pergroup

Groups can have sub groups which have subgroups and so on….

11


GROUP BY in Query Designer


GROUP BY Problem

Not an aggregateor group

You will see this error a lot. Not to worry. It happens to everyone!

12


Group By Results


Having

Restricts the groups returned

Operates on the groups after they have beenformed

HAVING(((Admissions.Diag_Code)

Like "a*"))

13


Having – SQL View

Restricts the groups returned

Operates on the groups after they have been formed


HAVING

14


HAVING Results


AIN102

Access Query DesignPart 2 – Joins, Subqueries

15


Database DesignDiagram of the database for reference in joins


Joins

Used to combine columns from morethan one table

Several types– Inner– Outer

Left Right

– Others (not covered) Full Outer (Not supported in Access) Cross Self Non equal

16


Inner Join

Pairs each row from first table withcorresponding row from second table overthe “join column” or “linking column”

The result only contains rows where there isa match over the join column in both tables

The default join in most databases


Inner Join Syntax

Basic SQL 92 Syntax:

SELECT column-list

FROM table1 [AS alias]

INNER JOIN table2 [AS alias]

ON join-condition

17


Table Aliases

Shorthand name for a table

Used in more complex queries

Select t.id, s.lnameFrom _traveler as tInner join xLU_Staff as sOn t.staffid = s.staffid

Table alias


Inner Join Basic SQL Example

Basic Example: Add patient names to

admissions data

Two join tables

Join condition

18


Inner Join Query Design


Inner Join Results

19


Inner Join over Multiple columns

Note that that the join condition can apply tomultiple columns if desired

Used with composite keysSelect ….From tablea as taInner join tableb as tbOn ta.key1 = tb.key1And ta.key2 = tb.key2


Joining More than Two Tables

Can join several tables in one select

Try to limit to three or four

Demonstration example

20


3 Table Query Results


More on Aliases

Can be set in QueryDesigner, too, byright clicking on atable

Useful for debuggingtop level queries aswe shall see later

21


Outer Joins

Left– selects all rows from the left or first table, even if no match

exists in the other table

– Widely used in commercial practice, esp. for reporting

Right– same idea but all rows from right table

Full

– all rows from both tables; not supported in Access


Left Outer Join

Basic SQL 92 Syntax:

SELECT column-list

FROM table1

LEFT JOIN table2

ON join-condition

22


Left Outer Join(Right click on relationship to edit)


Left Outer Join

Modify your prior inner join touse a left join

Save as qryLeft_Admit

Now run both the inner andleft joins

What is the difference?

23


Left Outer Join Results


Subqueries

One select statement embedded in another

Can be nested multiple levels deep

In Access query designer can be placed incriteria row or field row

24


Multi-valued Subquery

A type of subquery that compares to a list Ex: find all diagnostic codes with no admissions Commonly encountered in commercial practice


Multi-valued Subquery

Place subquery in criteria row

25


Multi-valued Subquery Result

No one was ever admitted with these diagnoses.


Single-valued Subquery

Subquery that returns a single value

Find all admissions with stays greater than the average stay

26


Single-valued Subquery

Subquery that returns a single value


Single-valued Subquery Result

27


Queries using Queries

Queries can be read just like a table

Some are updateable

Using a query as a source for another queryvery common in Access – especially forcomplicated queries

In a “back end” database such as Oracle orSQL Sever you would use a View


Queries using QueriesFilter the prior query ( a little on the complicated side)for the year 2001

28


Queries using Queries Result


AIN102

Access Query Design

Part 3 – Unions, Action Queries

D. H. D’Urso and Associates949-489-1472http://www.dhdursoassociates.com

29


Special Queries

Most are “Action Queries”

Reached through Query pull-down menu


Special Queries

Special action queries have distinct symbols

30


Admissions Database

Diagram of the database for reference in part 3


Data Modification Queries

SQL Action Query

INSERT Append

UPDATE Update

DELETE Delete

SELECT…INTO Maketable

31


Creating Action Queries

First set up the select query based on thetable you are selecting from

Test select query

Then convert to action query

When you run an action query there is noresult displayed – must look at theaffected table to see the result


Select Into…Maketable

Creates a new table “on the fly”

32


Select Into…Maketable

New table

Existing table

Make Table


Archived Labor History

33


Delete SQL

Deletes one or more rows

Basic Syntax:

DELETE FROM table-name

WHERE filter-criteria


Delete

Example:Delete allarchivedrecordsnewer than12/31/2001

34


Delete SQL

Example: Delete all archivedadmissions_history newer than 12/31/01


Archive after DELETE

35


More complex DELETE with FROMclause

Can delete based on matchingrecords in other tables

Uses from for criteria instead ofwhere – uses the matched rows asan implicit filter condition

Covered in advanced class


Append Query (SQL Insert)

Adds new rows to an existing table

Two forms:

– Single Row

– Multi-Row

36


Single Row Insert

Basic Syntax:

Insert [into] table-name

Values (value-list)


Single Row Insert

Basic Example:

INSERT into xLU_BuildStyle

values(6, “Thick”)

Not really used this way in MS Access. Typical MSAccess use would be Insert…Select as shown infollowing slides.

37


Append Query (Multi-row insert)


Multi-row Insert SQL

Basic Syntax:

INSERT [INTO] table-name

SELECT select-statement

38


Multi-row Insert (Append)

Add back archived admissions_historynewer than 12/31/01


Append (Insert) Results

39


Update

Updates fields in an existing row

Basic Syntax:

UPDATE table-name

SET field1 = new value, field2 = new value,…

WHERE selection-criteria


Update in Query Designer

New value

40


Update

Increase the admission_history copays by 10%(unrealistic to change history but we don’t want to step on ourgood tables)


Update Results

New values

Remember: you have to look at the affected table.No “result” is displayed.

41


Unions

Combines the results of two queries– Ex: current records and history

Tables must be union compatible (at least in theory!) There is no designer in Access; must be done in SQL view


Union Syntax

SELECT column-list

FROM table1

UNION [ALL]

SELECT same-columns

FROM table2

42


Union Example


Union Result

43


End Session 2

End of Class!

Notes


44

Notes


Notes


Accelerated Computer Training for Working Professionals

Orange Coast Database Associates Course (800)355-9855 or http://ocdatabases.itgo.com

Orange CoastDatabase Associates

Specializing in Microsoft Office,

Access, SQL, and related technologiesComputer Training, Programming & Consulting

32422 Alipaz St., Suite A-15

San Juan Capistrano, CA

(800)355-9855 (Toll Free) | (949)489-1472 (Direct) | (949)485-6284 (Fax)

http://www.dhdursoassociates.com | [email protected]

Accelerated Computer Training

AIN102 Microsoft Access Queries

Technology

san juan capistrano

date function month

back end database

sql view

action query

action queries

query designer

ms access