+------+-------+---------+--------+
| id   | title | content | parent | etc...
+------+-------+---------+--------+
| 1    | test1 | ...     | 2      |
| 2    | test2 | ...     | 4      |
| 3    | test3 | ...     | 2      |
| 4    | test4 | ...     | 1      |
| 5    | test5 | ...     | 2      |
+------+-------+---------+--------+