在sql触发器中使用else时出错

Question

我不确定我的代码有什么问题.

 delimiter $$
 CREATE TRIGGER updateRestaurantAtributes 
 AFTER UPDATE ON fields_data
 FOR EACH ROW BEGIN
 IF (NEW.fieldid = 1) THEN
    UPDATE restaurants
    SET address1 = NEW.data_txt 
    Where rid = NEW.itemid;
 ELSE IF (NEW.fieldid = 2) THEN
    UPDATE restaurants
    SET address2 = NEW.data_txt 
    Where rid = NEW.itemid;
 END IF;
END$$

以上版本无效.它说"END"(最后一行)附近的语法错误.但是当我使用它时,它会起作用

delimiter $$
CREATE TRIGGER updateRestaurantAtributes 
AFTER UPDATE ON fields_data
FOR EACH ROW BEGIN
IF (NEW.fieldid = 1) THEN
    UPDATE restaurants
    SET address1 = NEW.data_txt 
    Where rid = NEW.itemid;
END IF;
IF (NEW.fieldid = 2) THEN
    UPDATE restaurants
    SET address2 = NEW.data_txt 
    Where rid = NEW.itemid;
END IF;
END$$

我不知道为什么.我错过了什么吗？

Answer 1

而不是ELSE IF,MySQL的语法使用ELSEIF(没有空间).

 delimiter $$
 CREATE TRIGGER updateRestaurantAtributes 
 AFTER UPDATE ON fields_data
 FOR EACH ROW BEGIN
 IF (NEW.fieldid = 1) THEN
    UPDATE restaurants
    SET address1 = NEW.data_txt 
    Where rid = NEW.itemid;
 ELSEIF (NEW.fieldid = 2) THEN
    UPDATE restaurants
    SET address2 = NEW.data_txt 
    Where rid = NEW.itemid;
 END IF;
END$$

虽然您可以ELSE IF通过添加额外的空间来使其与空间一起使用END IF.通过使用空格,您可以有效地启动第二个IF语句,该语句必须独立于第一个外部IF语句而关闭.

/* Might work */
delimiter $$
 CREATE TRIGGER updateRestaurantAtributes 
 AFTER UPDATE ON fields_data
 FOR EACH ROW BEGIN
 IF (NEW.fieldid = 1) THEN
    UPDATE restaurants
    SET address1 = NEW.data_txt 
    Where rid = NEW.itemid;
 /* Opens a seconds IF block which must be closed */
 ELSE IF (NEW.fieldid = 2) THEN
    UPDATE restaurants
    SET address2 = NEW.data_txt 
    Where rid = NEW.itemid;
  /* Close inner IF block */
  END IF;
 END IF;
END$$