下面是获取仪表板屏幕数据的查询。
SELECT COUNT(*) as occupied_rooms FROM rooms where available='N' ;
SELECT COUNT(*) as checkedIn_guests FROM booking where checkout_time='' ;
SELECT COUNT(*) as available_rooms FROM rooms where available='Y' ;
SELECT COUNT(*) as total_guest FROM booking;
SELECT COUNT(*) as total_booking FROM booking;
SELECT COUNT(*) as total_staff FROM employee;
它产生如上所示的输出
我多么希望上面的图像输出如此。
最佳答案
您可以使用联合来生成行中每个结果的单个表结果
SELECT 'occupied_rooms', COUNT(*) count
FROM rooms
where available='N'
UNION
SELECT 'checkedIn_guests', COUNT(*)
FROM booking
where checkout_time=''
UNION
SELECT 'available_rooms', COUNT(*)
FROM rooms
where available='Y'
UNION
SELECT 'total_guest', COUNT(*)
FROM booking
UNION
SELECT 'total_booking', COUNT(*)
FROM booking
UNION
SELECT 'total_staff', COUNT(*)
FROM employee;
关于mysql - SQL合并不同的表数据计数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/57445130/