使用 Union 加入 SQL select 语句

Question

我正在尝试使用 Union All 加入三个 select 查询，但显示错误。当我加入前两个 select 语句时它工作正常。当我添加第三条语句时，我无法执行它。

SQL查询

WITH CTE_BOOKINGS (TotalRecurrance,TotalBookingsWithoutRecurrance,TotalBookingsWithRecurrance,RoomID) AS
(
SELECT 0,count(BK.pkBookingID) as TotalBookingsWithoutRecurrance,0, RM.roomID as RoomID
FROM dbo.tblBooking BK WITH (NOLOCK)
INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
WHERE
BK.deleteBooking=0
AND BDT.UTC_bookingEnd > GETUTCDATE()
AND BI.primaryRoom=1
AND BI.Active=1
AND NOT EXISTS (select * from tblBookingRecurrance where fkBookingID=BK.pkBookingID AND ACTIVE=1)
AND RM.roomID=16867
group by RM.roomID

UNION ALL
 
SELECT count(distinct BR.fkRecurranceID) as TotalRecurrance,0,0, RM.roomID as RoomID
FROM dbo.tblBooking BK WITH (NOLOCK)
INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
INNER JOIN tblBookingRecurrance BR WITH (NOLOCK) ON BK.pkBookingID=BR.fkBookingID
WHERE
BK.deleteBooking=0
AND BDT.UTC_bookingEnd > GETUTCDATE()
AND BI.primaryRoom=1
AND BI.Active=1
AND RM.roomID=16867
AND BR.active=1
group by RM.roomID

UNION ALL

SELECT 0,0,count(BK.pkBookingID) as TotalBookingsWithRecurrance, RM.roomID as RoomID
FROM dbo.tblBooking BK WITH (NOLOCK)
INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
WHERE
BK.deleteBooking=0
AND BDT.UTC_bookingEnd > GETUTCDATE()
AND BI.primaryRoom=1
AND BI.Active=1
AND RM.roomID=16867
group by RM.roomID
)

SELECT  SUM(TotalRecurrance + TotalBookingsWithoutRecurrance) as TotalBookings, TotalBookingsWithRecurrance, RoomID FROM CTE_BOOKINGS Group BY RoomID order by 1 desc

当我运行查询时显示以下错误：

错误

Column 'CTE_BOOKINGS.TotalBookingsWithRecurrance' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

Answer 1

您遇到的错误与 UNION 无关。第三个查询有错误。您需要先修复它，然后才能将其加入其他 2 个。

如果您按单个字段分组，则该字段将是唯一没有聚合函数的可选字段。这是一个 post 更深入的解释。

查看您的查询，您正在过滤特定的 roomId，不确定您的确切目标是什么，但在这种情况下，您不需要按 roomId 分组。

Answer 2

使用 UNION 时，将为整个结果集返回第一个 SELECT 中的列名。因此，即使您指定了“TotalBookingsWithoutRecurrance”、“TotalRecurrance”和“TotalBookingsWithRecurrance”，您的结果集（给定您当前的示例）列 header 也将是“TotalRecurrance”。

我相信你的问题出在你的最后 SELECT:

SELECT  SUM(TotalRecurrance + TotalBookingsWithoutRecurrance) as TotalBookings, TotalBookingsWithRecurrance, RoomID FROM CTE_BOOKINGS Group BY RoomID order by 1 desc

TotalBookingsWithRecurrance 没有被分组，您也没有执行某种聚合——因此出现错误。

要保持原样，您需要做的是：

SELECT SUM(TotalRecurrance + TotalBookingsWithoutRecurrance) as TotalBookings, TotalBookingsWithRecurrance, RoomID 
FROM CTE_BOOKINGS 
GROUP BY RoomID, TotalBookingsWithRecurrance
ORDER BY 1 DESC

但是，这将添加一个我怀疑您不想要的额外分组级别。

此外，您的列在 UNIONed 语句之间似乎没有对齐，这是必须的——至少是最佳实践（无论如何对我而言）。

我无法对此进行测试，但请尝试执行以下操作：

WITH CTE_BOOKINGS ( RoomID, RecurranceType, Recurrance, UnknownCol1, UnknownCol2  ) 
AS (    
    SELECT 
        RM.roomID AS RoomID,
        'TotalBookingsWithoutRecurrance' AS RecurranceType,
        COUNT ( BK.pkBookingID ) AS Recurrance,
        0 AS UnknownCol1,
        0 AS UnknownCol2
    FROM dbo.tblBooking BK WITH (NOLOCK)
    INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
    INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
    INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
    WHERE BK.deleteBooking=0
        AND BDT.UTC_bookingEnd > GETUTCDATE()
        AND BI.primaryRoom=1
        AND BI.Active=1
        AND NOT EXISTS (select * from tblBookingRecurrance where fkBookingID=BK.pkBookingID AND ACTIVE=1)
        AND RM.roomID=16867
    GROUP BY RM.roomID
    UNION ALL
    SELECT 
        RM.roomID AS RoomID,
        'TotalRecurrance' AS RecurranceType,
        COUNT ( DISTINCT BR.fkRecurranceID ) AS Recurrance,
        0 AS UnknownCol1,
        0 AS UnknownCol2 
    FROM dbo.tblBooking BK WITH (NOLOCK)
    INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
    INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
    INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
    INNER JOIN tblBookingRecurrance BR WITH (NOLOCK) ON BK.pkBookingID=BR.fkBookingID
    WHERE BK.deleteBooking=0
        AND BDT.UTC_bookingEnd > GETUTCDATE()
        AND BI.primaryRoom=1
        AND BI.Active=1
        AND RM.roomID=16867
        AND BR.active=1
    GROUP BY RM.roomID
    UNION ALL
    SELECT 
        RM.roomID AS RoomID,
        'TotalBookingsWithRecurrance' AS RecurranceType,
        COUNT ( BK.pkBookingID ) AS Recurrance, 
        0 AS UnknownCol1,
        0 AS UnknownCol2
    FROM dbo.tblBooking BK WITH (NOLOCK)
    INNER JOIN dbo.tblBookingItem BI WITH (NOLOCK) ON BK.pkBookingID=BI.fkBookingID
    INNER JOIN dbo.tblBookingDateTime BDT WITH (NOLOCK) ON BK.pkBookingID=BDT.fkBookingID
    INNER JOIN Enterprise.tblRooms RM WITH (NOLOCK) ON BI.fkItemID=RM.roomID AND RM.fkResourceId=1
    WHERE BK.deleteBooking=0
        AND BDT.UTC_bookingEnd > GETUTCDATE()
        AND BI.primaryRoom=1
        AND BI.Active=1
        AND RM.roomID=18841
    GROUP BY RM.roomID
)
SELECT
    SUM ( 
        CASE WHEN RecurranceType IN ( 'TotalRecurrance', 'TotalBookingsWithoutRecurrance' ) THEN Recurrance ELSE 0 END 
    ) AS TotalBookings, 
    SUM ( 
        CASE WHEN RecurranceType = 'TotalBookingsWithRecurrance' THEN Recurrance ELSE 0 END 
    ) AS TotalBookingsWithRecurrance, 
    RoomID 
FROM CTE_BOOKINGS
GROUP BY RoomID
ORDER BY 1 DESC;

使用 Union 加入 SQL select 语句

Join SQL select statements using Union

sql

sql-server

union-all