mysqli db：在多表上使用计数查询的最佳方法

Question

我需要在多个表上运行此查询：

设备、设备_警报、设备_文件、设备_FP、设备_用户

SELECT deviceID, COUNT(acepted) AS TT
FROM devices  
WHERE acepted = 0 
GROUP BY deviceID;

并获取每个接受=0的设备ID的总行数

这是获得结果的最佳方式。使用 union all 或者有不同的方式

SELECT deviceID, COUNT(*) AS TT
FROM (
    SELECT deviceID, acepted
    FROM devices
    WHERE acepted = 0

    UNION ALL

    SELECT deviceID, acepted
    FROM device_alarms
    WHERE acepted = 0

    UNION ALL

    SELECT deviceID, acepted
    FROM device_files
    WHERE acepted = 0

    UNION ALL

    SELECT deviceID, acepted
    FROM device_FP
    WHERE acepted = 0

    UNION ALL

    SELECT deviceID, acepted
    FROM device_users
    WHERE acepted = 0
) AS all_tables
GROUP BY deviceID;

或者这个在性能方面更好

SELECT 
    deviceID,
    SUM(TT) AS total_count
FROM (
    SELECT deviceID, COUNT(acepted) AS TT
    FROM devices
    WHERE acepted = 0
    GROUP BY deviceID

    UNION ALL

    SELECT deviceID, COUNT(acepted) AS TT
    FROM device_alarms
    WHERE acepted = 0
    GROUP BY deviceID

    UNION ALL

    SELECT deviceID, COUNT(acepted) AS TT
    FROM device_files
    WHERE acepted = 0
    GROUP BY deviceID

    UNION ALL

    SELECT deviceID, COUNT(acepted) AS TT
    FROM device_FP
    WHERE acepted = 0
    GROUP BY deviceID

    UNION ALL

    SELECT deviceID, COUNT(acepted) AS TT
    FROM device_users
    WHERE acepted = 0
    GROUP BY deviceID
) AS counts
GROUP BY deviceID;

Answer 1

如果您的表存储相似的数据，为什么不将它们保存在一个表中并按类型列分开？我认为这会是更好的解决方案