我正在使用 MySQL 开发一个博客站点。我正在运行一个跨两个表运行的子查询。
DROP TABLE IF EXISTS `blog_entries`;
CREATE TABLE IF NOT EXISTS `blog_entries` (
`id` int(10) unsigned NOT NULL auto_increment,
`title` varchar(255) NOT NULL,
`slug` varchar(255) NOT NULL,
`live` boolean default FALSE,
`date` datetime NOT NULL,
`author` int(3) default 0,
`body` text NOT NULL,
`category` int(2) default 0,
`tags` varchar(255) default '',
UNIQUE KEY `id` (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `blog_entry_comments`;
CREATE TABLE IF NOT EXISTS `blog_entry_comments` (
`id` int(10) unsigned NOT NULL auto_increment,
`blog_entry_id` int(10) NOT NULL,
`live` boolean default FALSE,
`date` datetime NOT NULL,
`name` varchar(128) default '',
`email` varchar(128) default '',
`web` varchar(128) default '',
`comments` text NOT NULL,
UNIQUE KEY `id` (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
查询如下所示:
SELECT be.id, be.title,
(SELECT (COUNT(bec.blog_entry_id)) AS blog_entry_comments_total
FROM blog_entry_comments bec
WHERE be.id = bec.blog_entry_id),
(SELECT (COUNT(bec.blog_entry_id)) AS blog_entry_comments_disabled
FROM blog_entry_comments bec
WHERE be.id = bec.blog_entry_id AND bec.live = 0)
FROM blog_entries be;
现在我认为说'AS blog_entry_comments_total'和'AS blog_entry_comments_disabled'的位会将结果列命名为这些各自的名称,但正如您从下面得到的结果中看到的那样,我将整个子查询作为列名:
| id | title | (SELECT (COUNT(bec.blog_entry_id)) AS blog_entry_comments_total FROM blog_entry_comments bec WHERE be.id = bec.blog_entry_id) | (SELECT (COUNT(bec.blog_entry_id)) AS blog_entry_comments_disabled FROM blog_entry_comments bec WHERE be.id = bec.blog_entry_id AND bec.live = 0) |
+----+----------------
| 1 | Blog Entry One | 3 | 1
| 2 | New Post | 0 | 0
| 3 | Testing | 0 | 0
3 rows in set (0.00 sec)
我需要的是一个句柄,我可以用它来引用此列,这似乎没有提供一个合理命名的句柄。我正在寻找的是一个看起来像这样的结果集:
| id | title | blog_entry_comments_total | blog_entry_comments_disabled |
+----+----------------
| 1 | Blog Entry One | 3 | 1
| 2 | New Post | 0 | 0
| 3 | Testing | 0 | 0
3 rows in set (0.00 sec)
有什么我做错了吗?