例如。我有一个用于向数据库表添加列的数据库升级脚本。它看起来有点像这样:
IF NOT Exists(SELECT * FROM SysColumns sc, SysObjects so
WHERE sc.Name = 'dealer_number'
AND so.Name = 'collector'
AND so.Type= 'U'
AND so.id = sc.id)
BEGIN
-- SQL for creating column
END
ELSE
BEGIN
-- notify user that column already exists
END
如何通知用户该列已存在?