尝试从mysql触发器插入时出现语法错误

Question

I'm trying to create a trigger to insert into a new table using values from two different tables (I'm using MySQL 5.5.27).

I get a syntax error when I try this but cannot see where the error is.

    DECLARE _Token VARCHAR(255);
SELECT token INTO _Token FROM appusers ON username = NEW.username;
INSERT INTO queue (token, message) VALUES (_Token, NEW.milestone);

My assumption is that it doesn't like the DECLARE because when I use the following I get message that _Token is an undeclared variable.

  SELECT token INTO _Token FROM appusers ON username = NEW.username;
INSERT INTO queue (token, message) VALUES (_Token, NEW.milestone);

Answer 1

Try do it with a single insert statement

INSERT INTO queue (token, message)
SELECT token, NEW.milestone
  FROM appusers 
 WHERE username = NEW.username;