Question

I have a schema that essentially looks like this:

CREATE TABLE `data` (
  `id` int(10) unsigned NOT NULL,
  `title` text,
  `type` tinyint(4),
  `parent` int(10)
)

The type field is just an enum where 1 is a parent type, and 2 is a child type (in actuality there are many types, where some should behave like parents and some like children). The parent field indicates that a record is the child of another record.

I know this is probably not ideal for the query I want to build, but this is what I have to work with.

I would like to sort and group the data so that the parent records are sorted by title, and grouped under each parent is the child records sorted by title. Like so:

 ID | title       |type |parent 
--------------------------------
 4  | ParentA     | 1   |
 2  | ChildA      | 2   | 4
 5  | ChildB      | 2   | 4
 7  | ParentB     | 1   |
 9  | ChildC      | 2   | 7
 1  | ChildD      | 2   | 7

---

** Edit **

We should be able to take the type field out of the picture entirely. If parent is not null then it should be grouped underneath it’s parent.

Answer 1

SELECT * FROM `data` ORDER BY COALESCE(`parent`, `id`), `parent`, `id`