Manual:Category table/zh

category工作表追踪所有现有分类. 如果某事物在表中的某处有条目，则它是一个分类

Categories might not have corresponding pages, so they need to be tracked separately. ,, and   are signed to make underflow more obvious.

cat_id
Primary key

cat_title
Name of the category, in the same form as. (with underscores). If there is a category page corresponding to this category, by definition, it has this name (in the Category namespace).

cat_pages
Number of pages in the category. This number includes the number of subcategories and the number of files.

cat_subcats
Number of sub-categories in the category.

cat_files
Number of files (i.e. Image: namespace members) in the category.

cat_hidden
Was reserved for future use; apparently no one found a use for it because it was removed in v1.20. Instead, the status of hidden categories is stored in the table as the property "hiddencat" in.

架构摘要
+-+--+--+-+-++ +-+--+--+-+-++ +-+--+--+-+-++
 * Field      | Type             | Null | Key | Default | Extra          |
 * cat_id     | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
 * cat_title  | varbinary(255)   | NO   | UNI | NULL    |                |
 * cat_pages  | int(11)          | NO   | MUL | 0       |                |
 * cat_subcats | int(11)         | NO   |     | 0       |                |
 * cat_files  | int(11)          | NO   |     | 0       |                |

+-+-+--+-+-++ +-+-+--+-+-++ +-+-+--+-+-++
 * Field      | Type                | Null | Key | Default | Extra          |
 * cat_id     | int(10) unsigned    | NO   | PRI | NULL    | auto_increment |
 * cat_title  | varbinary(255)      | NO   | UNI | NULL    |                |
 * cat_pages  | int(11)             | NO   | MUL | 0       |                |
 * cat_subcats | int(11)            | NO   |     | 0       |                |
 * cat_files  | int(11)             | NO   |     | 0       |                |
 * cat_hidden | tinyint(3) unsigned | NO   |     | 0       |                |

索引
 +--++---+--+-+---+-+--++--++-+---+ +--++---+--+-+---+-+--++--++-+---+ +--++---+--+-+---+-+--++--++-+---+
 * Table   | Non_unique | Key_name  | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
 * category |         0 | PRIMARY   |            1 | cat_id      | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
 * category |         0 | cat_title |            1 | cat_title   | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
 * category |         1 | cat_pages |            1 | cat_pages   | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |