Question

我有1个内连接表

SELECT COUNT(*) as dirtyRoom FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code WHERE status = 'sPVDirty'   output :  dirtyRoom : 13


SELECT COUNT(*) as readyRoom FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code WHERE status = 'sPVReady'   output : readyRoom : 33

SELECT COUNT(*) as maintenanceRoom FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code WHERE status = 'sPVMaint' output : maintenanceRoom : 4

我想将不同条件的每个计数值分组到1个表中，其中3列显示每个值

输出表1

 dirtyRoom             readyRoom           maintenanceRoom
    13                     33                     4

怎么做？

Answer 1

试试这个

SELECT COUNT(IF(status='sPVDirty',status,0)) As DirtyRoom,
       COUNT(IF(status='sPVReady',status,0)) As ReadyRoom,
       COUNT(IF(status='sPVMaint',status,0)) As MaintenanceRoom 
FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code

或者：

SELECT SUM(IF(status='sPVDirty',1,0)) As DirtyRoom,
       SUM(IF(status='sPVReady',1,0)) As ReadyRoom,
       SUM(IF(status='sPVMaint',1,0)) As MaintenanceRoom 
FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code

所以你的输出将是

+------------+------------+--------------------+
| DirtyRoom  | ReadyRoom  |MaintenanceRoom     |
+------------+------------+--------------------+
| 13         | 33         |4                   |
+------------+------------+--------------------+

Answer 2

尝试

SELECT 
    IF(status = 'sPVDirty', count(status), 0) as dirtyRoom,
    IF(status = 'sPVReady', count(status), 0) as readyRoom,
    IF(status = 'sPVMaint', count(status), 0) as maintenanceRoom,
FROM t_room INNER JOIN t_room_type ON t_room.roomType = t_room_type.code

如何将同一表中不同条件的每个计数值分组为1个表

2 个答案: