将主ID保存在MySQL表的另一列中


Save primary ID in another column in MySQL Table

我有这个MySQL表:

    CREATE TABLE web_media_com (
    web_media_id INT AUTO_INCREMENT PRIMARY KEY,
    web_media_position INT(12),
    web_media_headline VARCHAR(76),
    web_media_description VARCHAR(680)
    );

我想在一个INSERT INTO查询中将主id添加到"web_media_position"中。因此,当"web_media_id"得到id 234时,"web_mmedia_position"应该得到相同的234数字。

现在我有这个:

    $mysql_query = "INSERT INTO `web_media_com` (web_media_position, web_media_headline, web_media_description) VALUES
    (LAST_INSERT_ID(), '".$web_media_headline."', '".$web_media_description."')";

但这并不奏效。有人能告诉我怎么做吗?谢谢

使用事务来防止并发插入之间的冲突。

在直接(非PHP)sql中,它看起来像:

START TRANSACTION;
   INSERT INTO web_media_com(columns)....
   SET @entry_id = LAST_INSERT_ID();
   UPDATE web_media_com set web_media_position = @entry_id 
      where web_media_id = @entry_id;
COMMIT;

(注意:我没有尝试这是一个小提琴。YMMV…)

最适合您的解决方案

$mysql_query =
 "INSERT INTO web_media_com 
    (web_media_position, web_media_headline, web_media_description) 
    select MAX('id')+1,'".$web_media_headline."','".$web_media_description."' 
      from web_media_com";