Question

我如何一起加入表1和表2？

表1：

SELECT Roomid, Room, Latitude, Longitude,
                ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) AS D
FROM Rooms
AS t1
WHERE Latitude>(:minLat) AND Latitude<(:maxLat)
                AND Longitude>(:minLon) AND Longitude<(:maxLon)
                AND ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) < (:rad)
ORDER BY D
limit 6

表2：

SELECT name, date, roomid, descr
FROM Events
AS t2   
WHERE date > NOW()
GROUP BY roomid
ORDER BY date

每当我尝试在t1.Roomid = t2.roomid上执行JOIN时，它都无效。

Answer 1

试试这个：

SELECT *
FROM
    (
        SELECT  Roomid, 
                Room, 
                Latitude, 
                Longitude,
                ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) AS D
        FROM Rooms
        WHERE   Latitude>(:minLat) AND 
                Latitude<(:maxLat) AND 
                Longitude>(:minLon) AND 
                Longitude<(:maxLon) AND 
                ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) < (:rad)
    ) t1
    INNER JOIN 
    (
        SELECT `name`, `date`, roomid, `descr`
        FROM `Events`
        WHERE `date` > NOW()
        GROUP BY roomid
    ) t2
    ON t1.RoomID = t2.RoomID
ORDER BY t1.D, t2.`Date`

Answer 2

SELECT * FROM
(
SELECT Roomid, Room, Latitude, Longitude,
                ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) AS D
FROM Rooms
AS t1
WHERE Latitude>(:minLat) AND Latitude<(:maxLat)
                AND Longitude>(:minLon) AND Longitude<(:maxLon)
                AND ACOS(SIN((:lat))*SIN(RADIANS(Latitude)) + COS((:lat))*COS(RADIANS(Latitude))*COS(RADIANS(Longitude)-(:lon)))*(:R) < (:rad)
ORDER BY D
limit 6
) A,
(
SELECT name, date, roomid, descr
FROM Events
AS t2   
WHERE date > NOW()
GROUP BY roomid
ORDER BY date
) B
WHERE A.Roomid = B.roomid;

Answer 3

@Maknelly：为什么这个加入对你不起作用，首先给出你想要加入的自己的代码.......然后我们可以进一步帮助你关注。

加入两个单独的表

3 个答案: