检查是否存在存储过程

Question

Does any body know why the following SQL returns a syntax error (Incorrect syntax near 'IF') in SQL Server 2012?

DROP PROCEDURE IF EXISTS MyStoredProcedure;

I know I can use the following instead:

IF EXISTS(SELECT 1 FROM sys.procedures 
      WHERE Name = 'MyStoredProcedure')

But I wonder why the first one produces the error.

Thanks!

Answer 1

This works:

IF EXISTS(SELECT 1 FROM sys.procedures 
      WHERE Name = 'MyStoredProcedure')
      print 'yes'
      -- drop procedure mystoredprocedure

You must have something else in your query window that's throwing the error, or you're running things in the wrong order.

For what it's worth, this is my "go to" for dropping/building procedures before I CREATE PROCEDURE ... all my saved proc scripts have this.

IF OBJECT_ID('dbo.uspSomeProcName') IS NOT NULL
BEGIN
    DROP PROCEDURE dbo.uspSomeProcName
    IF OBJECT_ID('dbo.uspSomeProcName') IS NOT NULL
        PRINT '<<< FAILED DROPPING PROCEDURE dbo.uspSomeProcName>>>'
    ELSE
        PRINT '<<< DROPPED PROCEDURE dbo.uspSomeProcName>>>'
END