Phil Brewster [email protected]. One of the first steps – identify the proper data types Decide how data (in columns) should be stored and used.

Phil [email protected]

One of the first steps – identify the proper data types

Decide how data (in columns) should be stored and used character, numeric, date-time, or other data type (binary,

enum, etc.)

Data types determine how you will be able to use data in queries and in application program coding (edit routines) Do you need to perform calculations on the data? Do you need the data to be ‘constant’ or ‘variable’? Must the values be unique (often required for primary keys)? Can there be ‘missing values’ (allow NULL)?

▪ ‘Missing’ -- NOT to be confused with zeroes or spaces or initial default values!

Set of rules against which to test a relational system (E.F. Codd, 1970)

1. All data represented as tables2. Logical representation independent

from physical storage3. Single high-level language to build

tables, insert/update/delete data4. Support relational operations

(select, project, join) and set operations (union, intersect, difference, division)

5. Support views (alternate ways of looking at tables)

6. Differentiate between unknown (null) and zero

7. Mechanisms to support security and authorization

8. Protect data integrity through transactions and recovery procedures

[summary slides for Codd’s Rules: courtesy Dr K. Sward]

SQL lets you interact with a relational database system

ISO standards – most commands are the same Yet, also different ‘dialects’ for major database

systems▪ Oracle, Microsoft SQL Server, DB2, MySQL

Need to compare syntax rules across systems you use

Administrative commands to create logical databases, tables, grant user permissions

Application/user commands to load data, insert and update rows, select and order data

One-to-many data relationships: primary foreign key

Many-to-many data relationships: junction tables

First Normal Form (1NF) Eliminate repeating groups in individual tables Create a separate table for each set of related data Identify each set of related data with a primary key

Second Normal Form (2NF) Create separate tables for sets of values that apply to multiple

records Relate these tables with a foreign key

Third Normal Form (3NF) – frequently this is ‘overkill’… Eliminate fields that do not depend on the key

http://support.microsoft.com/kb/283878

Can be shared by many applications, many users (clients) at once

Database environment Database security Database administration

For application programs (APIs) to access server, need database connectors (drivers) Remember JDBC for Java? – needs custom drivers ODBC for almost everything else

The Community Edition is free (no tech support unless you buy the licensed version)

The product is stable (since version 4) Scalable, good performance

An alternative to other databases (Microsoft, Oracle) but without as many utilities Oracle PL/SQL▪ a powerful way to integrate database logic with

application logic (adds procedural programming constructs like if-else to ‘pure’ SQL)

Microsoft SQL Server ▪ proprietary ‘hooks’ integrating with MS applications

Pick the installer for your favorite OS

MySQL Community Server: http://dev.mysql.com/downloads/mysql/

MySQL Workbench (GUI tools): http://dev.mysql.com/downloads/workbench/5.2.html

MySQL database connectors (future): http://dev.mysql.com/downloads/connector/

Initial access to the MySQL server as root Create a standard user id + password Grant permissions

then log back in as user and do not use root!

Create a database Create tables in the database Load data into the tables (student.txt,

course.txt) Run queries to view data, sort data, etc.

Add primary keys to the tables (student2.txt, course2.txt)

Create a junction table Use foreign key relationships to link

tables Insert rows

Run more complex queries using table joins

Use MySQL Workbench to complete these tasks with GUI tools (if time allows)