任何人都可以使用此代碼來幫助我嗎?錯誤代碼:1242.子查詢返回多於1行 - 函數
DROP FUNCTION IF EXISTS dislike;
DELIMITER //
CREATE FUNCTION dislike(disliked_id int(11)) RETURNS CHAR
BEGIN
DECLARE disliked_songs CHAR;
IF disliked_id = 1 THEN
SET disliked_songs = (SELECT song_title from songs
where like_flag IN (SELECT like_flag from songs where like_flag= 1));
ELSE
SET disliked_songs = (SELECT song_title from songs
where like_flag IN (SELECT like_flag from songs where like_flag= 0));
END IF;
RETURN disliked_songs;
END;
//
DELIMITER ;
select dislike(1);
我試圖調用功能,但這樣做會返回一個錯誤
不要害羞。什麼是錯誤? –
你認爲這些查詢究竟做了什麼? – Uueerdo
很明顯,函數的返回值是單個「char」。返回變量'disliked_songs'不會是char。 –