Question

Let say I have this table,

 ID         Name       Order
======== ========  =========
 1           d          1
 2           g          2
 3           b          3
 4           f          4
 5           a          5

Now, from my UI user can change the order by drag drop. For example, he can move an item d to to item a place. Then my table will look like,

 ID         Name       Order
======== ========  =========
 2           g          1
 3           b          2
 4           f          3
 1           d          4
 5           a          5

Can any one tell me the SQL? I have input of ID, OldOrder and NewOrder.

Answer 1

You don’t even need the ID parameter.

UPDATE
  yourTable
SET
  Order = (CASE WHEN     Order = @oldOrder THEN @newOrder
                WHEN @newOrder > @oldOrder THEN Order - 1
                                           ELSE Order + 1 END)
WHERE
     Order BETWEEN @oldOrder AND @newOrder
  OR Order BETWEEN @newOrder AND @oldOrder

• Anything above or below the original and new positions don’t need to be changed.
• Everything else moves up or down one.
• Except the original item, that moves to the new position.