Select back things that _don't_ exist
- by bobobobo
I have this table. I want to select back the items that don't exist already, so I can create them.
table tags
+---------+-------+
| tagId | name |
| 1 | C |
| 2 | DX |
| 3 | CG |
Say SQL looks like:
select name from tags where name in ( 'C', 'CG', 'RX' )
You get back 'C' and 'CG', so you know you have to create 'RX'.
Is there a way to get a MySQL statement like this to return 'RX' instead, when 'RX' doesn't already exist?
