MYSQL Regex Negative Lookahead alternative

I’m doing a query on a postcode/zip code field.
I’ve been doing a bit of research and negative lookaheads aren’t supported:

“MySQL supports POSIX regular expressions, not PCRE”

Is there an alternative solution to the below, using the regular expressions supported by MYSQL?

(?i)^W(?!C) — this is the solution in PHP

And an example query to the database

select postcode from `postcodes` WHERE LOWER(postcode) REGEXP '^W(?!C)'

Answer

In MySQL, you may use

WHERE postcode REGEXP '^W([^C]|$)'

([^C]|$) matches any char but C or end of string. Also, no need to use TOLOWER as the regex search is case insensitive by default.

See the online tests:

SELECT 'wc' REGEXP '^W([^C]|$)'; // => 0
SELECT 'wR' REGEXP '^W([^C]|$)'; // => 1
SELECT 'w' REGEXP '^W([^C]|$)';  // => 1