存储过程小技巧(2)从动态查询SQL中返回值给变量

1) DECLARE @tbname sysname,@sql varchar(100)
SET @sql='SELECT '+@tbname+'=name FROM sysobjects where id=1'
EXEC(@sql)
SELECT @tbname

2) declare @num int, @sqls nvarchar(4000)
set @sqls='select @a=count(*) from tableName '
exec sp_executesql @sqls,N'@a int output',@num output

3)

   Set @StrSQL = ''
   Set @StrSQL = '
   set @a=''''

   Select @a=@a + Cast(' + @IDField + ' As varchar(20)) +'','''+ '
   From
    '+ @TableName +'
   Where
    ParentID = ' + Cast(@NodeID As varchar(20))
   --print @StrSQL
   Exec sp_executeSQL @StrSQL, N'@a varchar(4000) output',@cNodeIDStr out 
   --print @cNodeIDStr