MySQL如果存在，则返回＆＃39; id＆＃39;字段else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IF的正确语法：

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