Mysql 选择3个内部联接的不同列

我想在这个sql语句中选择distinct RoomName，我不知道在这个sql语句中把distinct放在哪里

SELECT Distinct
R.RoomID,R.RoomName,RT.RTypeName,RT.RTypePrice,RB.RBedName,RB.RBedPrice,
G.GalName,G.GalPath

FROM tbRoom as R
   INNER JOIN tbRoomType as RT ON R.RTypeID = RT.RTypeID
   INNER JOIN tbRoomBed as RB ON R.RBedID = RB.RBedID
   INNER JOIN tbGallery as G ON R.GalID = G.GalID
WHERE R.RoomID NOT IN(
    SELECT RD.RoomID FROM tbReservationDetail as RD WHERE
    RD.ArrivalDate <= '$dep' AND RD.DepartureDate >= '$arr' AND R.RoomID =
    RD.RoomID
)

试试这个：

SELECT R.RoomID,R.RoomName,RT.RTypeName,RT.RTypePrice,RB.RBedName,RB.RBedPrice, G.GalName,G.GalPath
FROM tbRoom AS R
INNER JOIN tbRoomType AS RT ON R.RTypeID = RT.RTypeID
INNER JOIN tbRoomBed AS RB ON R.RBedID = RB.RBedID
INNER JOIN tbGallery AS G ON R.GalID = G.GalID
WHERE R.RoomID NOT IN(
    SELECT RD.RoomID 
    FROM tbReservationDetail AS RD 
    WHERE RD.ArrivalDate <= '$dep' AND RD.DepartureDate >= '$arr' AND R.RoomID = RD.RoomID
)
GROUP BY R.RoomName;

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您是否使用DISTINCT和未使用DISTINCT进行了检查，结果是什么？使用DISTINCT是什么意思？您只希望每个roomname显示一次吗？如果是，您希望在选择中显示哪些其他数据？请从…中选择不同的R.RoomName！？！？！