Manual:Category table

Track all existing categories. Something is a category if 1) it has an entry somewhere in categorylinks, or 2) it once did. Categories might not have corresponding pages, so they need to be tracked separately.

DESCRIBE category

As noted in the sql:


 * cat_id - Primary key


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

The numbers of member pages (including categories and media), subcategories, and Image: namespace members, respectively. These are signed to make underflow more obvious. We make the first number include the second two for better sorting: subtracting for display is easy, adding for ordering is not.


 * cat_pages
 * cat_subcats
 * cat_files


 * cat_hidden - Reserved for future use