Question

我有两张名为： train_information 和轴的表。

Train_information

有以下内容：

train_id (PK)
train_name
train_length
number_of_axles

axle

有以下内容：

axle_id (PK)
train_id(FK)
axle

当我在 train_information 上插入内容时，让我们说例如将数字16放在 number_of_axles 中。我希望表轴能够自动获取相同的信息。

如何使用触发器执行此操作？

编辑：

现在使用此代码：

CREATE TRIGGER TriggerName AFTER INSERT ON train_information
FOR EACH
ROW 
BEGIN 
INSERT INTO axle( train_id, axle ) 
VALUES (
NEW.train_id, NEW.number_of_axles
);

END

但是现在，它输入了表轴中的数字16 但我希望它像：

axle_id = 1
train_id = 1
axle = 1

axle_id = 2
train_id = 1
axle = 2

axle_id = 3
train_id = 1
axle = 3

这是可能的吗？

Answer 1

您可以在AFTER TRIGGER表格上创建Train_information，如下所示：

<强> SQL 有关After Triggers in SQL

的更多信息

CREATE TRIGGER TriggerName
   ON Train_information
   FOR INSERT
   AS
   BEGIN
      SET NOCOUNT ON
      INSERT INTO axle
        (train_id, axle)
    SELECT
        train_id, 'axle_name'
        FROM inserted
    END

<强>的MySQL 有关After Triggers in MySQL

的更多信息

DELIMITER $$
CREATE TRIGGER TriggerName
   AFTER INSERT ON Train_information FOR EACH ROW
   BEGIN
      INSERT INTO axle (train_id, axle)
      VALUES (NEW.train_id, NEW.axle_name)            
    END;
$$
DELIMITER ;

触发器插入多个表

1 个答案: