如何在存储过程中删除和创建表? [英] how to drop and create a table in a stored procedure?

问题描述

我有一个存储过程，它将通过复制旧表 table1 的结构来创建一个新表 table1A%yyyymm%.但是在创建新表之前，我需要检查该表是否存在，如果存在，我需要先删除该表.这是我的存储过程.

I have a stored procedure which will create a new table table1A%yyyymm% by duplicating the structure of an old table, table1. But before I create the new table, I need to check if the table exist or not, if exists, I need to drop the table first. Here is my stored procedure.

DECLARE @yyyymm char(6)
SET @yyyymm=CONVERT(nvarchar(6), GETDATE(), 112)


DECLARE @tableName varchar(50)
SET @tableName='table1A_' + @yyyymm 

DECLARE @SQL varchar(max)
SET @SQL = 'DROP TABLE ' + @tableName

IF EXISTS (SELECT * FROM sys.tables WHERE type='u' and name =@tableName)
EXEC(@SQL) print (@sql)


SET @SQL= 'SELECT TOP 0 * 
INTO ' + @tableName + ' FROM table1 with (nolock)'
EXEC(@SQL)

但是如果表存在，我总是收到如下错误.哪里错了?

But if the table exists, I always got an error like following. Where is wrong?

DROP TABLE table1A_201404
Msg 2714, Level 16, State 6, Line 1
There is already an object named 'table1A_201404' in the database.

推荐答案

让我难住了...在这种情况下，似乎如果存在"与 exec 不能很好地协同工作.更新脚本如下:

Had me stumped... Seems the "If Exists" does not work well together with exec in this case. Updated script below:

DECLARE @yyyymm char(6)
SET @yyyymm=CONVERT(nvarchar(6), GETDATE(), 112)

DECLARE @tableName varchar(50)
SET @tableName='table1A_' + @yyyymm 

DECLARE @SQL varchar(max)
SET @SQL = 'DROP TABLE ' + @tableName

EXEC('IF EXISTS(SELECT * FROM sys.tables WHERE type=''u'' and name = N''' + @tablename + ''') DROP TABLE table1A_201404')

SET @SQL= 'SELECT TOP 0 * 
INTO ' + @tableName + ' FROM sysobjects with (nolock)'
EXEC(@SQL) print @SQL

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