MySQL Orderby a number, Nulls last
Currently I am doing a very basic OrderBy in my statement.
SELECT * FROM tablename WHERE visible=1 ORDER BY position ASC, id DESC
The problem with this is that NULL entries for 'position' are treated as 0. Therefore all entries with position as NULL appear before those with 1,2,3,4. eg:
NULL, NULL, NULL, 1, 2, 3, 4
Is there a way to achieve the following ordering:
1, 2, 3, 4, NULL, NULL, NULL.
MySQL has an undocumented syntax to sort nulls last. Place a minus sign (-) before the column name and switch the ASC to DESC:
SELECT * FROM tablename WHERE visible=1 ORDER BY -position DESC, id DESC
It is essentially the inverse of position DESC
placing the NULL values last but otherwise the same as position ASC
.
A good reference is here http://troels.arvin.dk/db/rdbms#select-order_by
I found this to be a good solution for the most part:
SELECT * FROM table ORDER BY ISNULL(field), field ASC;
NULL LAST
SELECT * FROM table_name ORDER BY id IS NULL, id ASC
Something like
SELECT * FROM tablename where visible=1 ORDER BY COALESCE(position, 999999999) ASC, id DESC
Replace 999999999 with what ever the max value for the field is
You can swap out instances of NULL with a different value to sort them first (like 0 or -1) or last (a large number or a letter)...
SELECT field1, IF(field2 IS NULL, 9999, field2) as ordered_field2
FROM tablename
WHERE visible = 1
ORDER BY ordered_field2 ASC, id DESC