Ordering by specific field value first

I have a table with 3 columns:

id | name | priority
--------------------
 1 | core  |   10
 2 | core  |   9
 3 | other |   8
 4 | board |   7
 5 | board |   6
 6 | core  |   4

I want to order the result set using priority but first those rows that have name=core even if have lower priority. The result should look like this

id | name | priority
--------------------
 6 | core  |   4
 2 | core  |   9
 1 | core  |   10
 5 | board |   6
 4 | board |   7
 3 | other |   8

Solution 1:

There's also the MySQL FIELD function.

If you want complete sorting for all possible values:

SELECT id, name, priority
FROM mytable
ORDER BY FIELD(name, "core", "board", "other")

If you only care that "core" is first and the other values don't matter:

SELECT id, name, priority
FROM mytable
ORDER BY FIELD(name, "core") DESC

If you want to sort by "core" first, and the other fields in normal sort order:

SELECT id, name, priority
FROM mytable
ORDER BY FIELD(name, "core") DESC, priority

There are some caveats here, though:

First, I'm pretty sure this is mysql-only functionality - the question is tagged mysql, but you never know.

Second, pay attention to how FIELD() works: it returns the one-based index of the value - in the case of FIELD(priority, "core"), it'll return 1 if "core" is the value. If the value of the field is not in the list, it returns zero. This is why DESC is necessary unless you specify all possible values.

Solution 2:

Generally you can do

select * from your_table
order by case when name = 'core' then 1 else 2 end,
         priority 

Especially in MySQL you can also do

select * from your_table
order by name <> 'core',
         priority 

Since the result of a comparision in MySQL is either 0 or 1 and you can sort by that result.

Solution 3:

One way to give preference to specific rows is to add a large number to their priority. You can do this with a CASE statement:

  select id, name, priority
    from mytable
order by priority + CASE WHEN name='core' THEN 1000 ELSE 0 END desc

Demo: http://www.sqlfiddle.com/#!2/753ee/1