MySQL 5.0 Triggers MySQL 5.0 New Features Series Part 2

Short Description
This book is for long-time MySQL users who want to know “what’s new” in version 5. The short answer is “stored procedures, triggers, views, information_schema”. The long answer is the “MySQL 5.0 New Features” series, and this book is the second in the series.

Website: dev.mysql.com | Filesize: 114kb
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Content
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We are including support for triggers in MySQL 5.0 for these reasons:
. Users of earlier MySQL versions kept on telling us they wanted triggers.
. We have a commitment to support all ANSI-standard features.
. You can use them to check for, and prevent, bad data entering the database.
. You can change or negate the INSERT, UPDATE, and DELETE statements.
. You can monitor data-change activity throughout a session.
I assume that you have read the first book in the “MySQL New Features” series already. In that book, “MySQL Stored Procedures”, you (I hope) saw how MySQL supports stored procedures and functions. That’s important knowledge, because you can use the same statements in triggers as you can use in functions. Specifically:
. Compound statements (BEGIN / END) are legal.
. Flow-of-control statements (IF, CASE, WHILE, LOOP, WHILE, REPEAT, LEAVE, ITERATE) are legal.
. Variable declaration (DECLARE) and assignment (SET) are legal.
. Condition declarations are legal.
. Handler declarations are legal.
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