1 Welcome to the World of Databases! Database technology: crucial to the operation and management of modern organisations Major transformation in computing skills Significant time commitment Exciting journey ahead

2 Subject Goals First course in database management Practical  Query formulation for application development  Data modeling and normalisation  Background about database administration No theoretical proofs or axioms

3 University Database

4 Water Utility Database

5 DBMS Marketplace Enterprise DBMS  Oracle: dominates in Unix; strong in NT  SQL Server: strong in NT  Informix: significant Unix market share  DB2: strong in mainframe environment Desktop DBMS  Access: dominates  FoxPro, Paradox, Approach, FileMaker Pro Open-source DBMS  MySQL  PostgreSQL

6 Tables Relational database is a collection of tables Heading: table name and column names Body: rows, occurrences of data Student

7 Entity Integrity: primary keys  Each table has column(s) with unique values … the primary key  No two rows with the same primary key value  No null values in a primary key

8 The “Faculty” Table

9 What is SQL? Structured Query Language Language for database definition, manipulation, and control International standard Standalone and embedded usage “Intergalactic database-speak”

10 First “SELECT” Examples See slide 8 for the “faculty” table … Example 1 SELECT * FROM Faculty; … will list everything in the “Faculty” table. Example 2 SELECT FacFirstName, FacLastName, FacSalary FROM Faculty; … will just list those three columns.

11 First SELECT Examples Example 3 SELECT FacFirstName, FacLastName, FacSalary FROM Faculty WHERE FacSalary > 65000; … will just list those with a salary greater than $65000.

12 Other Single Table Examples Example 4 SELECT FacFirstName, FacLastName, FacSalary FROM Faculty WHERE FacSalary > AND FacRank = 'PROF‘; Example 5: Testing for null values SELECT OfferNo, CourseNo FROM Offering WHERE FacSSN IS NULL; … NULL is not the same thing as zero!