MySQL Stored Procedure Programming

Chapter 3. Language Fundamentals

This chapter introduces the MySQL stored program language, a simple, readable but complete programming language based on the ANSI SQL:2003 SQL/PSM (Persistent Stored Module) specification.

The MySQL stored program language is a block-structured language (like Pascal) that includes familiar statements for manipulating variables , implementing conditional execution, performing iterative processing, and handling errors. Users of other stored program languages such as Oracle PL/SQL or Microsoft SQL Server Transact-SQL will find features of the language very familiar. In fact, users of the IBM DB2 SQL Procedural language will find MySQL’s stored program language almost identical—both are based on the SQL/PSM specification. Users of other programming languages that are typically used with MySQL—such as PHP, Java, or Perl—might find the stored program language a little verbose, but should have no difficulty at all learning the language.

In this chapter we will look at the fundamental building blocks of the stored program language—variables, literals, parameters, comments, operators, expressions, and data types. We will also discuss MySQL 5 “strict” mode and its implications. In the next chapter we will build on this base by describing the block structure, conditional statements (IF and CASE), and looping capabilities of the language.