php - How to escape parentheses in a REGEXP clause -

in database have keys this:

custom_field_languages(0)language custom_field_languages(1)language custom_field_languages(2)language ...

and need of them. doesn't work:

regexp '^custom_field_languages([0-9])language'

this doesn't work.

regexp '^custom_field_languages\([0-9]\)language'

this works isn't 100% accurate.

regexp '^custom_field_languages.[0-9].language'

what correct way escape normal parentheses?

you can escape parentheses square brackets, this:

regexp '^custom_field_languages[(][0-9][)]language'

this useful when need embed query string language provides own interpretation backslashes inside string literals.

JVParth