sql - SQL Server 2008 R2 中的动态 WHERE 子句

Question

我有一个使用动态条件WHERE子句查询的表。WHERE当所有列都为空或某些列具有某些值时，我正在寻找一种获得简单条件的最佳方法。

我试过这样的事情：

SET @CONDITIONS = CASE 
    WHEN @VEHICLE_TYPE_NAME IS NULL
        THEN '  ISNULL(A.VEHICLE_TYPE_NAME,'''') = ISNULL(A.VEHICLE_TYPE_NAME,'''') '
    ELSE '  A.VEHICLE_TYPE_NAME = ''' + @VEHICLE_TYPE_NAME + ''''
    END + ' ' + CASE 
    WHEN CAST(@PRODUCT_ID AS VARCHAR(MAX)) IS NULL
        THEN ' AND ISNULL(A.PRODUCT_ID, ''-1'') = ISNULL(A.PRODUCT_ID, ''-1'') '
    ELSE ' AND  A.PRODUCT_ID =  ''' + CAST(@PRODUCT_ID AS VARCHAR(MAX)) + ''''
    END + ' ' + CASE 
    WHEN CAST(@CAPABILITY_ID AS VARCHAR(MAX)) IS NULL
        THEN ' AND  ISNULL(A.CAPABILITY_ID,''-1'') = ISNULL(A.CAPABILITY_ID,''-1'') '
    ELSE ' AND  A.CAPABILITY_ID = ''' + CAST(@CAPABILITY_ID AS VARCHAR(MAX)) + ''''
    END + ' ' + CASE 
    WHEN @SPONSOR_FIRM_ID IS NULL
        THEN ' AND  ISNULL(A.SPONSOR_FIRM_ID,'''') = ISNULL(A.SPONSOR_FIRM_ID,'''') '
    ELSE ' AND  A.SPONSOR_FIRM_ID = ''' + @SPONSOR_FIRM_ID + ''''
    END + ' ' + CASE 
    WHEN @CLIENT_FIRM_ID IS NULL
        THEN ' AND  ISNULL(A.CLIENT_FIRM_ID,'''') =  ISNULL(A.CLIENT_FIRM_ID,'''')  '
    ELSE ' AND  A.CLIENT_FIRM_ID = ''' + @CLIENT_FIRM_ID + ''''
    END + ' ' + CASE 
    WHEN CAST(@DIST_PLATFORM_ID AS VARCHAR(MAX)) IS NULL
    THEN ' AND ISNULL(A.DIST_PLATFORM_ID,''-1'') = ISNULL(A.DIST_PLATFORM_ID,''-1'') '
    ELSE ' AND  A.DIST_PLATFORM_ID = ''' + CAST(@DIST_PLATFORM_ID AS VARCHAR(MAX)) + ''''
    END + ' ' + CASE 
    WHEN @RR_INTERNAL_NUMBER IS NULL
        THEN 'AND ISNULL(A.RR_INTERNAL_NUMBER,'''') =  ISNULL(A.RR_INTERNAL_NUMBER,'''') '
    ELSE ' AND  A.RR_INTERNAL_NUMBER = ''' + @RR_INTERNAL_NUMBER + ''''
    END

Answer 1

Why do you need dynamic SQL?

WHERE (@VEHICLE_TYPE_NAME IS NULL OR A.VEHICLE_TYPE_NAME = @VEHICLE_TYPE_NAME)
      AND (@PRODUCT_ID IS NULL OR A.PRODUCT_ID = @PRODUCT_ID)
      ...

Answer 2

您不需要参数为空的部分。您可以简单地为每个部分构建一个动态 SQL

IF @PRODUCT_ID IS NOT NULL
   @CONDITIONS = @CONDITIONS + ' AND  A.PRODUCT_ID =  ''' + CAST(@PRODUCT_ID AS VARCHAR(MAX)) + ''''