Question

我有一个查询，我需要将其作为动态查询运行，以输出有意义的列名。例如，如果我直接运行查询，它会正确返回数据。但是，如果我使用下面的代码，它会显示：

The name '
            SELECT (CASE WHEN A.Domain IS NOT NULL THEN A.Domain ELSE B.Domain END) AS [Domain], 
                    (CASE WHEN A.Email IS NOT NULL THEN A.Email ELSE B.Email END) AS [Email], 
                    A.[Sender Size] AS [Sender Size 1], A.[Sender Count] AS [Sender Count 1],
                        A.[Receiver Size] AS [Receiver Size 1], A.[Receiver Count] AS [Receiver Count 1],
                    A.[Sender Size 2] AS [Sender Size 2], A.[Sender Count 2] AS [Sender Count 2],
                        A.[Receiver Size 2] AS [Receiver Size 2], A.[Receiver Count 2] AS [Receiver Count 2],
                    B.SenderSize AS [Sender Size Average], B.SenderCount AS [Sender Count Average],
                        B.ReceiverSize AS [Receiv' is not a valid identifier.

下面是代码：

DECLARE @query NVARCHAR(4000)
SET @query = N'SELECT *
            FROM
            (
                SELECT (CASE WHEN A.Domain IS NOT NULL THEN A.Domain ELSE B.Domain END) AS [Domain], 
                        (CASE WHEN A.Email IS NOT NULL THEN A.Email ELSE B.Email END) AS [Email], 
                        A.[Sender Size] AS [Sender Size 1], A.[Sender Count] AS [Sender Count 1],
                            A.[Receiver Size] AS [Receiver Size 1], A.[Receiver Count] AS [Receiver Count 1],
                        A.[Sender Size 2] AS [Sender Size 2], A.[Sender Count 2] AS [Sender Count 2],
                            A.[Receiver Size 2] AS [Receiver Size 2], A.[Receiver Count 2] AS [Receiver Count 2],
                        B.SenderSize AS [Sender Size Average], B.SenderCount AS [Sender Count Average],
                            B.ReceiverSize AS [Receiver Size Average], B.ReceiverCount AS [Receiver Count Average]
                FROM
                    (
                    SELECT (CASE WHEN tf.Domain IS NOT NULL THEN tf.Domain ELSE tf2.Domain END) AS Domain, 
                            (CASE WHEN tf.Email IS NOT NULL THEN tf.Email ELSE tf2.Email END) AS Email, 
                         ISNULL(tf.SenderSize,0) AS [Sender Size] , ISNULL(tf.SenderCount,0) AS [Sender Count], ISNULL(tf.ReceiverSize,0) AS [Receiver Size], ISNULL(tf.ReceiverCount,0) AS [Receiver Count], 
                         ISNULL(tf2.SenderSize,0) AS [Sender Size 2], ISNULL(tf2.SenderCount,0) AS [Sender Count 2], ISNULL(tf2.ReceiverSize,0) AS [Receiver Size 2], ISNULL(tf2.ReceiverCount,0) AS [Receiver Count 2] 
                    FROM #TrafficFinal tf FULL JOIN #TrafficFinal2 tf2 ON (tf.Email = tf2.Email AND tf.Domain = tf2.Domain)
                    ) A FULL JOIN #TrafficFinal3 B ON (A.Email = B.Email AND A.Domain = B.Domain)
            ) C
            ORDER BY Domain, Email';    

PRINT @query;

-- run it
exec @query;

是否因为完全加入？

Answer 1

最后尝试这个：

exec (@query)

如果没有括号，SQL Server会将变量的值假定为存储过程名称。

OR

EXECUTE sp_executesql @query

这不应该是因为完全加入但是我希望你已经创建了临时表：＃TrafficFinal，＃TrafficFinal2，＃TrafficFinal3之前。

请注意，使用EXEC和sp_executesql之间存在性能问题。因为sp_executesql像sp一样使用强制语句缓存更多细节here。

另一方面，你是否有理由在这种情况下使用动态sql，当你可以按原样使用查询时，考虑到你没有进行任何查询操作并按原样执行它？

Answer 2

在我的情况下，如果您的sql是通过连接或使用转换生成的，那么执行时的sql需要以字母N为前缀，如下所示

e.g。

Exec N'Select bla..'

N定义字符串文字是unicode。

exec失败，因为名称不是有效的标识符？

2 个答案: