The Basics of the SQL Database

As we said, SQL (Structured Query language) is the language of choice for most modern multi-user, relational databases. That is because SQL provides the syntax and idioms (language) you need to talk to (query) relational databases in a standardized, cross-platform/product way (structured).

The beauty of SQL is that it idiomizes the relational model. Rather than refer to data as a set of pointers, SQL provides predefined procedures to allow you to use any value in a table to relate other tables in a database. So long as a database is structured using the relational model, SQL will be a natural fit because SQL was designed to make sense in a relational system. SQL by its very design is a language that can be used to talk about relating tables.

For the rest of Part One and Two, we will examine how you will use SQL to access relational databases. However, first we should say a little bit about the structure of SQL databases before we plunge into usage.

SQL databases (most modern relational databases), as you will recall, are composed of a set of row/column-based "tables", indexed by a "data dictionary". To access data in the tables, you simply use SQL to navigate the system and produce "views" based on search criteria defined in the SQL query.

Okay, that was quite a bit of jargon all at once. Let's step back for a moment and look at each of these terms.

Talking to Databases
Introduction to Databases for the Web | Table of Contents
SQL Tables