Question

我有2个表环境和房间：

Environment
+-------+------------+--------------+----------------------+
| Envid | Agregate   | Availability | RoomNo               |
+-------+------------+--------------+----------------------+

Room
+--------+----------+-------------+------------------+
| RoomNo | Humidity | Temperature | Lighting         |
+--------+----------+-------------+------------------+
|  1     |    50    |  40         |  9               |
|  2     |    79    |  25         |  7               |
|  3     |    50    |  40         |  9               |
+--------+----------+-------------+------------------+

基本上，环境是一张空桌子。我需要的是自动计算：

从EACH ROW上的Room中获取湿度，温度和光照值
将它们总结在一起。我能够做到这一点 -

SELECT RoomNo，Humidity，Temperature，Lighting，Humidity + Temperature + Lighting AS Agregate FROM Room;

我只需要：

将环绕表中新计算的“Agregate”存储为“Agregate”
使用表格的相应房间号码填充（通过外键）。

编辑： 5.房间的可用性（布尔值），当Agregate＆gt;时应更新为1。 100。

这可以直接在mysql中完成吗？还是用PHP？

注意：Environment中的RoomNo是外键房间主键

Answer 1

使用以下触发器填充Environment表。

delimiter |
CREATE TRIGGER `after_update_Room` 
  AFTER UPDATE ON `Room` FOR EACH ROW 
    BEGIN 
      UPDATE Environment
      SET Agregate = NEW.Humidity + NEW.Temperature + NEW.Lighting
      WHERE RoomNo = NEW.RoomNo;
    END;
|

delimiter |
CREATE TRIGGER `after_insert_Room`
    AFTER INSERT ON `Room` FOR EACH ROW
    BEGIN
       INSERT INTO Environment (`Agregate`, `RoomNo`) 
       SELECT Humidity+Temperature+Lighting AS Agregate, RoomNo 
       FROM Room 
       WHERE RoomNo = NEW.RoomNo;
    END;
|

自动化mysql表中的数据计算

1 个答案: