Question

我有一个如下的SQL查询：

    Declare @ConnectionType int = 5, 
    @UserId int = 2

    select * from CallDetails 
    Where ((@ConnectionType = 0 AND CallDetails.DeviceType IN (0,1,2,3,4,5,7,8))
            OR (@ConnectionType = 1 AND CallDetails.DeviceType = 4)
            OR (@ConnectionType = 2 AND CallDetails.DeviceType IN (0,1,2,3,7))
            OR (@ConnectionType = 3 AND CallDetails.DeviceType = 5)
            OR (@ConnectionType = 4 AND CallDetails.DeviceType IN (0,1,2,3,4,7))
            OR (@ConnectionType = 5 AND CallDetails.DeviceType IN (4,5))
            OR (@ConnectionType = 6 AND CallDetails.DeviceType IN (0,1,2,3,5,7))
            OR (@ConnectionType = 7 AND CallDetails.DeviceType IN (8))
            OR (@ConnectionType = 8 AND CallDetails.DeviceType IN (0,1,2,3,7,8))
            OR (@ConnectionType = 9 AND CallDetails.DeviceType IN (5,8))
            OR (@ConnectionType = 10 AND CallDetails.DeviceType IN (4,8))
            OR (@ConnectionType = 11 AND CallDetails.DeviceType IN (0,1,2,3,4,8))
            OR (@ConnectionType = 12 AND CallDetails.DeviceType IN (0,1,2,3,5,8))
            OR (@ConnectionType = 13 AND CallDetails.DeviceType IN (4,5,8)) 
            OR (@ConnectionType = 14 AND CallDetails.DeviceType IN (0,1,2,3,7,4,5))
            OR @ConnectionType IS NULL)

查询的另一部分是：

            AND (@UserId IS NULL OR @ConnectionType IN (1,3,5,7,9,10,13)

            OR (@ConnectionType = 0 AND (CallDetails.DeviceType IN (4,5,8) OR (CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 2 AND ((CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 4 AND (CallDetails.DeviceType = 4 OR (CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 6 AND (CallDetails.DeviceType = 5 OR (CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 8 AND (CallDetails.DeviceType = 8 OR (CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 11 AND (CallDetails.DeviceType IN (4,8) OR (CallDetails.UserId = @UserId)))
            OR (@ConnectionType = 12 AND (CallDetails.DeviceType IN (5,8) OR (CallDetails.UserId = @UserId))) 
            OR (@ConnectionType = 14 AND (CallDetails.DeviceType IN (4,5) OR (CallDetails.UserId = @UserId)))
        )

@ConnectionType是多个设备的组合，将在此基础上确定DeviceType。将来，将添加任何其他设备@ConnectionType，组合将会增加，依此类推。该查询也正在多个Store Procedures中使用。如何优化此查询？

Answer 1

正如我提到的那样，使用查找表看起来会更好。您的表可能看起来像这样简单（请注意，我没有添加索引，外键约束等，但是您可能会想要/需要它们）：

CREATE TABLE dbo.ConnectionLookup (ConnectionType int,
                                   DeviceType int);

INSERT INTO dbo.ConnectionLookup (ConnectionType,
                                  DeviceType)
VALUES(0,0),
      (0,1),
      (0,2),
      (0,3),
      (0,4),
      (0,5),
      (0,7),
      (0,8),
      (1,4),
      ...
      (14,0),
      (14,1),
      (14,2),
      (14,3),
      (14,4),
      (14,5),
      (14,7);

然后，您可以在查找表上执行JOIN：

DECLARE @ConnectionType int = 5;
        --@UserId int = 2; --Commented out, as never used.

SELECT {Your Columns}
FROM dbo.CallDetails CD
     JOIN dbo.ConnectionLookup CL On CD.DeviceType = CL.DeviceType
WHERE CL.ConnectionType = @ConnectionType;

但是，这有点猜测，因为缺少示例数据和预期结果，但应该（无不多）使您走上正确的道路

Answer 2

您可以通过以下几种方法进行优化： 1.在where子句的列上添加索引，这可以加快查询速度 2.创建一个具有ConnectionType，DeviceType的帮助器表（关联表）并将其联接 3.调整存储过程并使用动态查询，如下所示：

DECLARE @ConnectionType INT = 0,
   @UserId INT = 2,
   @DeviceTypeString NVARCHAR(100) = NULL

IF @ConnectionType = 0
   SET @DeviceTypeString = N'0,1,2,3,4,5,7,8'

IF @ConnectionType = 1
    SET @DeviceTypeString = N'4'

IF @ConnectionType = 2
   SET @DeviceTypeString = N'0,1,2,3,7'

IF @ConnectionType = 3
    SET @DeviceTypeString = N'5'

IF @ConnectionType = 4
    SET @DeviceTypeString = N'0,1,2,3,4,7'

IF @ConnectionType = 5
    SET @DeviceTypeString = N'4,5'

IF @ConnectionType = 6
    SET @DeviceTypeString = N'0,1,2,3,5,7'

IF @ConnectionType = 7
    SET @DeviceTypeString = N'8'

IF @ConnectionType = 8
    SET @DeviceTypeString = N'0,1,2,3,7,8'

EXEC sp_executesql N'SELECT * FROM CallDetails AS cd WHERE (@1 IS NULL OR @1 = @1) AND (cd.DeviceType IN (SELECT [Value] FROM STRING_SPLIT(@2, '','')) OR cd.UserID = @3)',
    N'@1 INT, @2 NVARCHAR(100), @3 INT',
    @ConnectionType,
    @DeviceTypeString,
    @UserID

我不想变得固执，已经改了我的示例以与sp_executesql;-）

Answer 3

您可以创建一个具有两列（ConnectionType，DeviceType）的表，其中每一种连接类型都有多个记录。然后将通话详细信息与此表联系起来。

如何使用多个OR，AND，IN语句优化查询？

3 个答案: