Question

I have a table like this

id    title    display_order
1     t1       3
2     t2       1
3     t3       5
4     t4       4
5     t5       2
6     t6       0
7     t7       7
8     t8       6
9     t9       0
10    t10      0

What I need is to have results like this

id    title    display_order
2     t2       1
5     t5       2
1     t1       3
4     t4       4
3     t3       5
8     t8       6
7     t7       7
...order of the rest is not important but should be in the result
6     t6       0
9     t9       0
10    t10      0

I can get this result with two SQL queries and then combine them.

Is there a way to do this with one SQL?

Thanks

Answer 1

SELECT *
FROM atable
ORDER BY
  display_order = 0,
  display_order

When display_order is 0, the first sorting term, display_order = 0, evaluates to True, otherwise it evaluates to False. True sorts after False – so, the first sorting criterion makes sure that rows with the display_order of 0 are sorted at the end of the list.

The second ORDER BY term, display_order, additionally specifies the order for rows with the non-zero order values.

Thus, the two criteria give you the desired sorting order.