MYSQL REGEXP for text not between parentheses

Question

I'm looking to search a large MYSQL table for a string and only return results that aren't between parentheses. If my table looks like this:

| ID |Data |
| 1 |Some search term here |
| 2 |Search term |
| 3 |Search term (search term) |
| 4 |(Search term) search term |
| 5 |Here's the (search term) |
| 6 |Never match this line |

And I want to select the rows where "search term" (case-insensitive) appears, but not in parentheses, how can I write the REGEXP to achieve that?

IDs 1,2,3,4 should return. IDs 5 & 6 shouldn't.

The search term may include letters, numbers and punctuation (though it shouldn't need to support parentheses as they'll never be nested).

Answer 1

I hate regex(or dont get them) so:

SELECT id,data FROM table 
WHERE CONCAT(REPLACE(SUBSTRING_INDEX(data,'(',1),'(',''),
REPLACE(SUBSTRING_INDEX(data,')',-1),')','')) 
LIKE '%search term%';

SQL Fiddle