+------------+
| users |
+------------+
| avatar |
| created_at |
| email |
| id |
| password |
| signature |
| updated_at |
| username |
+------------+
+------------+
| friends |
+------------+
| avatar |
| created_at |
| email |
| id |
| note_name |
| state |
| tag_id |
| unread_cnt |
| updated_at |
| user_id |
+------------+
+---------------+
| group_members |
+---------------+
| created_at |
| group_id |
| id |
| nickname |
| updated_at |
| user_id |
+---------------+
+------------+
| groups |
+------------+
| avatar |
| created_at |
| id |
| name |
| creator_id |
| readme |
| room_key |
| unread_cnt |
| updated_at |
+------------+
+-------------+
| messages |
+-------------+
| content |
| created_at |
| file_size |
| id |
| media_type |
| receiver_id |
| room_key |
| sender_id |
| state |
| type |
+-------------+
+------------+
| msg_stats |
+------------+
| created_at |
| id |
| room_key |
| total |
| updated_at |
+------------+
+------------+
| tags |
+------------+
| created_at |
| id |
| name |
| updated_at |
| user_email |
| user_id |
+------------+