[SOLVED] Reorder rows in a MySQL table

Reorder rows in a MySQL table

I have a table:

+--------+-------------------+-----------+
| ID     | Name              |  Order    |
+--------+-------------------+-----------+
| 1      | John              | 1         |
| 2      | Mike              | 3         |
| 3      | Daniel            | 4         |
| 4      | Lisa              | 2         |
| 5      | Joe               | 5         |
+--------+-------------------+-----------+

The order can be changed by admin hence the order column. On the admin side I have a form with a select box Insert After: to entries to the database. What query should I use to order+1 after the inserted column.

I want to do this in a such way that keeps server load to a minimum because this table has 1200 rows at present. Is this the correct way to save an order of the table or is there a better way?

Any help appreciated

EDIT:

Here's what I want to do, thanks to itsmatt:

want to reorder row number 1 to be after row 1100, you plan to leave 2-1100 the same and then modify 1 to be 1101 and increment 1101-1200

Solution

You need to do this in two steps:

UPDATE MyTable 
   SET `Order` = `Order` + 1 
 WHERE `Order` > (SELECT `Order` 
                    FROM MyTable 
                   WHERE ID = <insert-after-id>);

...which will shift the order number of every row further down the list than the person you're inserting after.

Then:

INSERT INTO MyTable (Name, `Order`)
VALUES (Name, (SELECT `Order` + 1 FROM MyTable WHERE ID = <insert-after-id>));

To insert the new row (assuming ID is auto increment), with an order number of one more than the person you're inserting after.