SQL PRINT 与 SQL EXEC

Question

执行下面的查询时，如果我使用PRINT它打印正确。我可以复制并粘贴打印的代码并执行它。但是，如果我使用 EXEC，则会出现以下错误：

有没有办法简化我正在做的事情？为什么 SQLPRINT和 SQL 会EXEC提供这两种截然不同的结果集？

DECLARE @TableName as NVARCHAR(250), @SQL as VARCHAR(MAX);

DECLARE @TableCursor as CURSOR;
SET @TableCursor = CURSOR FOR
SELECT sobjects.name
FROM sysobjects sobjects
WHERE sobjects.xtype = 'U'
AND name like 'HISTORY_MasterList_%'
ORDER BY sobjects.name

OPEN @TableCursor;
FETCH NEXT FROM @TableCursor INTO @TableName;
WHILE @@FETCH_STATUS = 0
BEGIN
SET @SQL ='select '''+ @TableName +''', 0
 Union All
select All ''Server Count'',count(1) from ['+ @TableName +'] 
 Union All
select All ''Server Cores'',sum(convert(decimal(18,0),cores)) from ['+ @TableName +'] 
 Union All
select ''Production Servers'',count(1) from ['+ @TableName +'] where Classification in (''Prod'',''Production'',''Prd'',''Unknown'')
Union All
select ''Production Cores'', sum(convert(decimal(18,0),cores)) from ['+ @TableName +']
 where Classification in (''Prod'',''Production'',''Prd'',''Unknown'')
 Union All
select ''Production Server Count after filtering out passive/failover servers'', count(1) from 
(select  distinct m.ServerName
       from ['+ @TableName +']  m
       inner join [SQLEnv].[dbo].[vwManView] v on m.ServerName = v.ServerName
       where Classification in (''Prod'',''Production'',''Prd'',''Unknown'')
       and unit <> 0) aa
 Union All
select ''Production Server Cores after filtering out passive/failover servers'', sum(convert(decimal(18,0),cores)) from(
       select  distinct m.ServerName, m.Cores
       from ['+ @TableName +']  m
       inner join [SQLEnv].[dbo].[vwManView] v on m.ServerName = v.ServerName
       where Classification in (''Prod'',''Production'',''Prd'',''Unknown'')
       and unit <> 0) aa
 Union All
select ''Non-Prod SQL Instances downgraded to Developer Edition'',count(1) from ['+ @TableName +'] where ''InstanceStatus'' like ''Downgrade%''
 Union All
select ''Non-Prod SQL Instance Core Count downgraded to Developer Edition'',sum(convert(decimal(18,0),cores)) from ['+ @TableName +']  where ''InstanceStatus'' like ''Downgrade%''
 Union All
select ''Non-Prod VMs moved from Prod Environments'', count(1) from ['+ @TableName +']  where ServerStatus like ''VM Moved/right sized from Prod Env to NonProd''
 Union All
select ''Non-Prod VMs TO BE moved from Prod Environments'', count(1) from ['+ @TableName +']  where ServerStatus like ''Sent for V2V - non prod split'' 
'

EXEC @SQL

FETCH NEXT FROM @TableCursor INTO @TableName;
END
CLOSE @TableCursor;
DEALLOCATE @TableCursor;

Answer 1

错误是说...it is not a valid identifier。当您传递 时EXEC @SQL，它期望@sql代表存储过程（或标量函数）的名称。因此错误消息：...it is not a valid identifier。

如果要执行文本以动态传递 ，则应将该文本封装在 中( )，例如EXEC (@SQL)。