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我需要在使用 JOIN创建新表时cover_art引用的表中添加一个新列，但我不记得我是如何做到的。newsnewsdetails

这是包含表中artistid引用的 id 的artists表：

CREATE TABLE `news` (
`post_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
`artistid` smallint(5) unsigned NOT NULL,
`title` varchar(150) NOT NULL,
`cover_art` varchar(150) NOT NULL,
`blog_entry` text NOT NULL,
`updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`rating` varchar(150) NOT NULL,
PRIMARY KEY (`post_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=76 ;


INSERT INTO `news` (`post_id`, `artistid`, `title`, `cover_art`, `blog_entry`,     `updated`, `rating`) VALUES
(1, 1, 'Ultra', 'images/temp_cover.jpg', 'The very first track Barrel Of A Gun is blah blah.', '2012-11-19 16:23:19', '990,568'),
(2, 13, 'Mish Mash', 'images/temp_cover.jpg', 'A train pulls into a station and etc etc ad infinitum.', '2012-11-19 16:23:44', '831,880'),

这artists是具有我包含在其中的 id 的表news：

CREATE TABLE `artists` (
`id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
`artists_name` varchar(150) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=170 ;


INSERT INTO `artists` (`id`, `artists_name`) VALUES
(1, 'Depeche Mode'),
(2, 'Amon Tobin'),
Etc.

我已经考虑过进行内连接和左连接，但我一生都记不起我为创建这个变成的newsdata表所做的事情：artistidartists_name

1 post_id smallint(5) UNSIGNED No 0
2 title varchar(150) latin1_swedish_ci No None
3 blog_entry text latin1_swedish_ci No None
4 updated timestamp No 0000-00-00 00:00:00
5 rating varchar(150) latin1_swedish_ci No None
6 Artist_name varchar (150) latin1_swedish_ci 无 无

感谢 eggyal 让我知道外键是什么 - 即不这样做:-(

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1 回答 1

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SELECT news.post_id,
       news.title,
       news.blog_entry,
       news.updated,
       news.rating,
       artists.artists_name
FROM   news JOIN artists ON artists.id = news.artistid
于 2012-11-20T00:21:05.400 回答