如果MySQL存在，则返回字段的“id”，否则插入新行并返回最后插入的id？

Question

这句话有什么问题？

IF EXISTS (
SELECT * 
FROM `apples` 
WHERE `apples`.`color` = ? 
AND `apples`.`size` = ?) 
SELECT `apples`.`applesID` 
ELSE 
INSERT INTO `apples` (`color`, `size`) 
VALUES(?,?); 

Answer 1

您没有使用正确的语法IF：

IF EXISTS (
    SELECT * 
    FROM `apples` 
    WHERE `apples`.`color` = ? 
    AND `apples`.`size` = ?) THEN 
    SELECT `apples`.`applesID`; 
ELSE 
    INSERT INTO `apples` (`color`, `size`) VALUES(?,?); 
END IF;