光標的動態查詢

Question

我需要爲光標寫一個動態查詢來獲取表的索引名稱。

嘗試1：

DECLARE @Cur AS Cursor 

EXECUTE SP_EXECUTESQL N'SET @Cur = CURSOR fast_forward for 
         SELECT IndexColumn = i.name 
         FROM sys.indexes i 
         INNER JOIN sys.tables t ON t.object_id = i.object_id 
         WHERE 
         T.Name = ''' + @TableName + '''' 

錯誤：附近有語法錯誤 '+'。

嘗試2：

DECLARE @sqlstatement nvarchar(max) 

SET @sqlstatement = 'DECLARE @Cur AS CURSOR fast_forward for 
       SELECT IndexColumn = i.name 
       FROM sys.indexes i 
       INNER JOIN sys.tables t ON t.object_id = i.object_id 
       WHERE 
       T.Name = ''' + @TableName + '''' 
PRINT(@sqlstatement) 
EXEC sp_executesql @sqlstatement 

錯誤：附近有語法錯誤FAST_FORWARD'。

Answer 1

光標聲明是不正確的（失去@/AS）

SET @sqlstatement = 'DECLARE Cur CURSOR fast_forward for 
       SELECT IndexColumn = i.name 
       FROM sys.indexes i 
       INNER JOIN sys.tables t ON t.object_id = i.object_id 
       WHERE 
       T.Name = ''' + @TableName + '''' 

（未遂1是不正確的光標是不是在建字符串中的批次範圍內）

Answer 2

那麼有因爲遊標不在範圍內，所以不需要聲明。你也可以這樣做 -

SET @sqlstatement = 'DECLARE cur_mycursor CURSOR fast_forward for 
       SELECT IndexColumn = i.name 
       FROM sys.indexes i 
       INNER JOIN sys.tables t ON t.object_id = i.object_id 
       WHERE 
       T.Name = ''' + @TableName + '''' 
EXEC(@sqlstatement) 

OPEN cur_mycursor 

FETCH NEXT FROM cur_mycursor INTO .... blah..blah...