TSQL中exec的细微差别

Question

这个存储过程

CREATE PROC GetPage(@blockNumber int, @blockSize int = 40, @query varchar(1000)) 
AS
   DECLARE @a int = @blockNumber * @blockSize;
   DECLARE @b int = @a + @blockSize - 1;
   DECLARE @fromPos int = PATINDEX('% FROM %', @query);
   DECLARE @from varchar(1000) = SUBSTRING(@query, @fromPos, 1000);
   DECLARE @select varchar(1000) = SUBSTRING(@query, 1, @fromPos);
   DECLARE @SQL varchar(1000) = 
      'select *, ROW_NUMBER() over (order by ONE) R INTO #FOO FROM ('
      +@SELECT+',1 ONE'+@from+') T';

   EXEC @SQL;

   SELECT * FROM FOO WHERE RN BETWEEN @a AND @b;

   DECLARE @C INT = (SELECT COUNT(*) FROM #FOO);
   DROP TABLE #FOO
   RETURN @C;

传递时SELECT * FROM ASSET生成此SQL

select *, ROW_NUMBER() over (order by ONE) R INTO #FOO 
FROM (select * ,1 ONE from asset) T

当我从SQL Server Management Studio执行此操作时,如下所示:

exec('select *, ROW_NUMBER() over (order by ONE) R INTO #FOO FROM (select * ,1 ONE from asset) T')

它按预期创建表#FOO.

但是,执行存储过程时:

exec getpage 5,10,'select * from asset'

我收到这个错误

Msg 2812,Level 16,State 62,Procedure GetPage,Line 12
找不到存储过程'select*,ROW_NUMBER()over(order by ONE)R INTO FOO FROM(select*,1 ONE from asset)T'.
消息208,级别16,状态1,过程GetPage,第14行
无效的对象名称'#FOO'.

我认为第二个消息仅仅是第一个错误的结果.有谁知道为什么exec语句在存储过程中表现不同？

Answer 1

在你的exec中使用括号

EXEC (@SQL); 

执行(Transact-SQL)

没有括号,你使用这个:

Execute a stored procedure or function
[ { EXEC | EXECUTE } ]
    { 
      [ @return_status = ]
      { module_name [ ;number ] | @module_name_var } 
        [ [ @parameter = ] { value 
                           | @variable [ OUTPUT ] 
                           | [ DEFAULT ] 
                           }
        ]
      [ ,...n ]
      [ WITH  [ ,...n ] ]
    }
[;]

您需要在需要括号的地方.

Execute a character string
{ EXEC | EXECUTE } 
    ( { @string_variable | [ N ]'tsql_string' } [ + ...n ] )
    [ AS { LOGIN | USER } = ' name ' ]
[;]