Guru's Guide to SQL Server™ Stored Procedures, XML, and HTML, The

Best Practices

Triggers are really just stored procedures in disguise. They have a few additional capabilities and nuances, but generally speaking, you take the same approach to writing a trigger as you would to build a stored procedure. A few additional thoughts:

• Make sure your triggers allow for the possibility that more than one row could be altered at once. Triggers that work fine with single-row operations often break when multirow operations come their way. Not allowing for multirow updates is the single most common error that trigger neophytes make.

• Begin each trigger by checking @@ROWCOUNT to see whether any rows have changed. If none have, exit immediately because there's nothing for the trigger to do.

• Use the UPDATE() and COLUMNS_UPDATED() ...