Manual:User groups table

The user_groups table maps the users in a particular MediaWiki installation to their corresponding user rights. Each group can be assigned a mixture of permissions through  or via extensions; all users of a particular group have those permissions granted to them as a result of their membership in the group. As the table is separate from the table, this allows for the creation of a shared user database with permissions that vary from wiki to wiki within a wiki farm. This table was introduced on r5648, in MediaWiki 1.5. If you are using MediaWiki 1.3 or 1.4, have a look at. Before MediaWiki 1.5, user rights were stored in the field of the  table.

All unregistered users automatically belong to the group and only to that group; all registered users additionally are automatically part of the  group. User groups are additive; as a result, all registered users have all the privileges assigned to the group as well. Formerly there was a "sysop bit"; now, making a user a sysop adds a row to.

ug_user
This field links to a given user's. It is a foreign key used to link accounts with their assigned privileges.

ug_group
This field stores the user's permissions, which are stored as groups. At runtime,  will associate group keys with particular permissions; a user will have the combined permissions of any group they're explicitly in, plus the implicit and  groups. Example values: 'bot', 'bureaucrat', 'sysop'.

There is one row for each (explicit) group the user is in.

ug_expiry
This field stores a user group's expiry time. It is similar to pr_expiry in the table and ipb_expiry in the  table.

Schema summary
+---+--+--+-+-+---+ +---+--+--+-+-+---+ +---+--+--+-+-+---+
 * Field    | Type             | Null | Key | Default | Extra |
 * ug_user  | int(10) unsigned | NO   | PRI | 0       |       |
 * ug_group | varbinary(255)   | NO   | PRI |         |       |
 * ug_expiry | varbinary(14)   | YES  | MUL | NULL    |       |

+--+--+--+-+-+---+ +--+--+--+-+-+---+ +--+--+--+-+-+---+
 * Field   | Type             | Null | Key | Default | Extra |
 * ug_user | int(10) unsigned | NO   | PRI | 0       |       |
 * ug_group | varbinary(255)  | NO   | PRI |         |       |

+--+--+--+-+-+---+ +--+--+--+-+-+---+ +--+--+--+-+-+---+
 * Field   | Type             | Null | Key | Default | Extra |
 * ug_user | int(10) unsigned | NO   | PRI | 0       |       |
 * ug_group | varbinary(32)   | NO   | PRI |         |       |

+--+--+--+-+-+---+ +--+--+--+-+-+---+ +--+--+--+-+-+---+
 * Field   | Type             | Null | Key | Default | Extra |
 * ug_user | int(10) unsigned | NO   | PRI | 0       |       |
 * ug_group | varbinary(16)   | NO   | PRI |         |       |

+--+-+--+-+-+---+ +--+-+--+-+-+---+ +--+-+--+-+-+---+
 * Field   | Type            | Null | Key | Default | Extra |
 * ug_user | int(5) unsigned | NO   | PRI | 0       |       |
 * ug_group | char(16)       | NO   | PRI |         |       |

Indexes
 +-++---+--+-+---+-+--++--++-+---+ +-++---+--+-+---+-+--++--++-+---+ +-++---+--+-+---+-+--++--++-+---+
 * Table      | Non_unique | Key_name  | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
 * user_groups |         0 | PRIMARY   |            1 | ug_user     | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
 * user_groups |         0 | PRIMARY   |            2 | ug_group    | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
 * user_groups |         1 | ug_group  |            1 | ug_group    | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
 * user_groups |         1 | ug_expiry |            1 | ug_expiry   | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |

Default MediaWiki groups
In a default MediaWiki installation, ug_group can be one of the following:

++ ++ ++
 * ug_group  |
 * bot       |
 * bureaucrat |
 * sysop     |