插入后MySQL触发器打开

Question

我是MySQL新手.我有两个表total_loaner和available_loaner.我正在尝试为total_loaner中添加的每个新行创建一个触发器,我想将该新行添加到available_loaner.

这里我的表格如何:

CREATE TABLE `total_loaner` (
  `Kind` varchar(10) NOT NULL,
  `Type` varchar(10) NOT NULL,
  `Sno` varchar(10) NOT NULL,
  PRIMARY KEY (`Sno`)
)

CREATE TABLE `available_loaner` (
  `Kind` varchar(10) NOT NULL,
  `Type` varchar(10) NOT NULL,
  `Sno` varchar(10) NOT NULL,
  `Status` char(10) NOT NULL DEFAULT '',
  PRIMARY KEY (`Sno`)
) 

我的触发似乎不起作用.

CREATE TRIGGER new_loaner_added 
AFTER INSERT ON 'total_loaner' for each row
begin
INSERT INTO available_loaner (Kind, Type, Sno, Status)
Values (new.Kind, new.Type, new.Sno, 'Available');
END;

Answer 1

在你的情况下,你可以像这样重写你的触发器

CREATE TRIGGER new_loaner_added 
AFTER INSERT ON total_loaner
FOR EACH ROW 
  INSERT INTO available_loaner (Kind, Type, Sno, Status)
  VALUES (NEW.Kind, NEW.Type, NEW.Sno, 'Available');

注意:

• 从表名中删除单引号total_loaner,因为引号有效地使其成为字符串文字而不是正确的标识符.如果你愿意,你可以使用后退,但这是不必要的,因为它不是保留字,也不包含任何特殊字符.
• 因为它是一个单语句触发器现在你不需要使用DELIMITER命令和BEGIN...END块

这是SQLFiddle演示

Answer 2

您可能需要设置分隔符:

DELIMITER $$

CREATE TRIGGER new_loaner_added 
AFTER INSERT ON `total_loaner` for each row
begin
INSERT INTO available_loaner (Kind, Type, Sno, Status)
Values (new.Kind, new.Type, new.Sno, 'Available');
END$$

DELIMITER ;

现在,它在INSERT声明结尾处的分号与声明的结尾混淆了CREATE TRIGGER.

Answer 3

这个为我工作，更简化的版本。

CREATE TRIGGER new_loaner_added 
    AFTER INSERT ON `DB1`.`table_name`
    FOR EACH ROW 
      INSERT INTO `DB2`.`table_name` (messageID, conversationID, fromJID)
      VALUES (NEW.messageID,NEW.conversationID, NEW.fromJID);