Question

我试图更新一行，如果它存在，如果它不存在，那么我想在表中执行插入。 picture.id＆amp; picture.picturepath是一个唯一的密钥。我看了一些例子，但我不确定我做错了什么。

我遇到过重复密钥更新，不确定这是否与我想要实现的内容相关。

Error message: 1064- You have an error in your SQL syntax near 'UPDATE picture SET picture.picturecontent = ipicturecontent WHERE picture.id at line 5"


    IF EXISTS( SELECT * FROM picture WHERE picture.id = ipictureid 
    AND picture.picturepath = ipicturepath) THEN

    UPDATE picture 
    SET picture.picturecontent = ipicturecontent
    WHERE picture.id = ipictureid 
    AND picture.picturepath = ipicturepath

    ELSE

    INSERT INTO picture (picture.id, picture.picturecontent,picture.picturepath) VALUES (ipictureid, ipicturecontent, ipicturepath)

Answer 1

https://stackoverflow.com/a/10095812/1287480＆lt; - 信用到期的信用

INSERT INTO模型（col1，col2，col3）价值观（＆＃39; foo＆＃39;，＆＃39; bar＆＃39;，＆＃39; alpha＆＃39;） ON DUPLICATE KEY UPDATE col3 =＆＃39; alpha＆＃39;;

Answer 2

不要忘记THEN，BEGIN和END

IF EXISTS( SELECT * FROM picture WHERE id = ipictureid 
    AND picturepath = ipicturepath) 
    THEN
        BEGIN
            UPDATE picture 
               SET picturecontent = ipicturecontent
             WHERE id = ipictureid 
               AND picturepath = ipicturepath
        END;
ELSE
    BEGIN
        INSERT INTO picture (id,
                             picturecontent,
                             picturepath) 
                     VALUES (ipictureid, ipicturecontent, ipicturepath)
    END;
END IF;

如果存在然后更新MySQL

2 个答案: