By Welland Barn
The objective of this chapter is to introduce the main concepts of data storage and retrieval in the context of database information systems.
In view of their prominence this booklet concentrates on the general characteristics of Relational Database Management Systems (RDBMS) and the Structured Query Language SQL and does not consider any of the numerous other types of databases. No prior knowledge of SQL is assumed.
It is intended that the SQL presented in this booklet be followed interactively and that the you should try all the given examples in the order in which they are presented. At the end of the booklet you should have attained a thorough knowledge of SQL and its capabilities as an interactive statement language.
In the main the SQL covered complies with the standard definition for SQL were proprietary SQL features are referred to this will be made clear. On this basis the skills obtained from this unit should be transferable across a wide range of RDBMS's which support SQL.
To enable you to make effective use of your local facilities a number of RDBMS specific appendices containing access instructions and other supplementary information specific to your environment have been included.