[英]ORDER BY - many-to-many MySQL query
I have the following problem: I have 'content' table, which keeps main posts and objects in the system, 'custom_field' table, which enables use to add any custom field to a post and 'content_data' table, which holds custom field values. 我有以下问题:我有“内容”表和“ content_data”表,“内容”表将系统中的主要帖子和对象保留在系统中,“ custom_field”表可用于向帖子中添加任何自定义字段,而“ content_data”表则包含自定义字段值。
CREATE TABLE `cms_content` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`title` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
CREATE TABLE `cms_content_data` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`custom_field_id` int(11) NOT NULL,
`value` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`content_id` int(11) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `key` (`value`,`content_id`,`custom_field_id`) USING BTREE,
KEY `content_id` (`content_id`),
KEY `custom_field_id` (`custom_field_id`),
KEY `value` (`value`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
CREATE TABLE `cms_custom_field` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `name_2` (`name`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
Now, I want to be able to ORDER result set BY custom field value. 现在,我希望能够按自定义字段值对结果集进行排序。 Both custom_field.name column and content_data.value column are indexed, but that does not seem to help and the query is very slow.
custom_field.name列和content_data.value列都已建立索引,但这似乎无济于事,并且查询非常慢。 content_data.custom_field_id is certainly indexed as well.
当然也会为content_data.custom_field_id编制索引。
Here's my query: 这是我的查询:
SELECT `content`.`id`, `content_data`.`value` AS `title_sort`
FROM `content`
INNER JOIN `content_data` ON `content_data`.`content_id` = `content`.`id`
LEFT JOIN `custom_field` ON `custom_field`.`id` = `content_data`.`custom_field_id`
WHERE `custom_field`.`name` = 'title_sort'
ORDER BY `title_sort`
Is there any way to do it in a more optimized way? 有什么办法可以更优化地做到这一点?
Thank you in advance! 先感谢您!
I want to be able to ORDER result set BY custom field value.
我希望能够按自定义字段值对结果集进行排序。 Both custom_field.name column and content_data.value column are indexed
custom_field.name列和content_data.value列均已建立索引
You have entitled content_data.value
as the column to sort by. 您已将
content_data.value
为要作为排序依据的列。 That is a varchar(255) column. 那是一个varchar(255)列。 The real 'title_sort' is an indexed varchar(50) column from
custom_field.name
. 真正的'title_sort'是
custom_field.name
的索引varchar(50)列。
This is closer to your described requirement: 这更接近于您描述的要求:
SELECT
`content`.`id`
, `custom_field`.`name` AS `title_sort`
, `content_data`.`value`AS whatever_this_is
FROM `custom_field`
INNER JOIN `content_data` ON `custom_field`.`id` = `content_data`.`custom_field_id`
INNER JOIN `content` ON `content_data`.`content_id` = `content`.`id`
WHERE `custom_field`.`name` = 'title_sort'
ORDER BY `custom_field`.`name`
However, what you do want is very probably a sort on content_data
. 但是,您想要的很可能是对
content_data
的排序。 value
. value
。
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