手册:categorylinks表
| ↑ 手册:索引 | MediaWiki数据库布局 | categorylinks表 |
| MediaWiki版本： | ≥ 1.3 |
categorylinks表存储与[[Category:Title]]或[[Category:Title|sortkey]]形式的链接相对应的条目，当将其放置在页面上的任何位置时，该页面会将该页面放入名为的分类中“标题”（其关联页面可能存在，也可能不存在）。
以冒号开头的链接，如[[:Category:Title]]，不会存储在categorylinks表中，而是按正常的内部链接处理（在本例中指向页面 Category:Title）。
The editable parts of category pages are stored like other pages.
There are four indexes which help improve performance:
- The concatenation of
cl_fromandcl_to(for when an article is edited) - The concatenation of
cl_to,cl_type,cl_sortkey, andcl_from(for showing articles in order) - The concatenation of
cl_toandcl_timestamp - cl_collation
字段
cl_from
Stores the page.page_id of the article where the link was placed.
cl_to
Stores the name of the desired category in the page_title format (that is, with _ and excluding namespace prefix).
cl_sortkey
Stores the title by which the page should be sorted in a category list. This is the binary sortkey, that depending on $wgCategoryCollation may or may not be readable by a human (but should sort in correct order when comparing as a byte string), and is not valid UTF-8 whenever the database truncates the sortkey in the middle of a multi-byte sequence.
cl_timestamp
Stores the time at which that link was last updated in the table.
cl_sortkey_prefix
This is either the empty string if a page is using the default sortkey (aka the sortkey is unspecified).
Otherwise it is the human readable version of the first part of cl_sortkey.
Needed mostly so that cl_sortkey can be easily updated in certain situations without re-parsing the entire page.
More recently added values are valid UTF-8 (see gerrit:449280).
cl_collation
| MediaWiki版本： | ≥ 1.17 |
What collation is in use. Used so that if the collation changes, the updateCollation.php script knows what rows need to be fixed in db.
cl_type
What type of page is this (file, subcat (subcategory) or page (normal page)). Used so that the different sections on a category page can be paged independently in an efficient manner.
Schema summary
| MediaWiki版本： | ≥ 1.17 |
DESCRIBE categorylinks;
+-------------------+------------------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+------------------------------+------+-----+-------------------+-----------------------------+
| cl_from | int(10) unsigned | NO | PRI | 0 | |
| cl_to | varbinary(255) | NO | PRI | | |
| cl_sortkey | varbinary(230) | NO | | | |
| cl_sortkey_prefix | varbinary(255) | NO | | | |
| cl_timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| cl_collation | varbinary(32) | NO | MUL | | |
| cl_type | enum('page','subcat','file') | NO | | page | |
+-------------------+------------------------------+------+-----+-------------------+-----------------------------+
 警告： | Starting with version 1.17, the index on (cl_to, cl_sortkey) is no more, and replaced with one on (cl_to, cl_type, cl_sortkey, cl_from). Extensions that directly query the categorylinks table to get a list of pages in sorted order need to make sure they are using the new index, or the query may become very inefficient |
| MediaWiki版本： | 1.10 – 1.16 |
DESCRIBE categorylinks;
+--------------+------------------+------+-----+-------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +--------------+------------------+------+-----+-------------------+-----------------------------+ | cl_from | int(10) unsigned | NO | PRI | 0 | | | cl_to | varbinary(255) | NO | PRI | | | | cl_sortkey | varbinary(70) | NO | | | | | cl_timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | +--------------+------------------+------+-----+-------------------+-----------------------------+
| MediaWiki版本： | 1.5 – 1.9 |
DESCRIBE categorylinks;
+--------------+-----------------+------+-----+-------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +--------------+-----------------+------+-----+-------------------+-----------------------------+ | cl_from | int(8) unsigned | NO | PRI | 0 | | | cl_to | varchar(255) | NO | PRI | | | | cl_sortkey | varchar(86) | NO | | | | | cl_timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | +--------------+-----------------+------+-----+-------------------+-----------------------------+
| MediaWiki版本： | 1.3 – 1.4 |
DESCRIBE categorylinks;
+--------------+-----------------+------+-----+-------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +--------------+-----------------+------+-----+-------------------+-----------------------------+ | cl_from | int(8) unsigned | NO | PRI | 0 | | | cl_to | varchar(255) | NO | PRI | | | | cl_sortkey | varchar(255) | NO | | | | | cl_timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | +--------------+-----------------+------+-----+-------------------+-----------------------------+
索引
| MediaWiki版本： | ≥ 1.42 |
SHOW INDEX IN categorylinks;
+---------------+------------+--------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +---------------+------------+--------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | categorylinks | 0 | PRIMARY | 1 | cl_from | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 0 | PRIMARY | 2 | cl_to | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_sortkey | 1 | cl_to | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_sortkey | 2 | cl_type | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_sortkey | 3 | cl_sortkey | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_sortkey | 4 | cl_from | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_timestamp | 1 | cl_to | A | 0 | NULL | NULL | | BTREE | | | | categorylinks | 1 | cl_timestamp | 2 | cl_timestamp | A | 0 | NULL | NULL | | BTREE | | | +---------------+------------+--------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
参见
外部链接
- 示例 某个分类的页面列表。