Question

I am writing a custom search engine for my website. I am trying to make use of MySQL REGEXP feature. I would like to be able to search for a word separated by spaces to avoid the chances of getting suffixes or prefixes on a word. For example I am trying to search for “appreciate” I want appreciate, not appreciated or unappreciate or unappreciated. Any ideas on how I could do this with MySQL’s REGEXP? My idea for this was to look for spaces like maybe so:

^appreciate$|^appreciate[:space:]|[:space:]appreciate$|[:space:]appreciate[:space:]

I am sure they is a better way of doing it and I have no idea if that even works

Answer 1

I think what you want is something like this:

SELECT 'I appreciate you' REGEXP '[[:<:]]appreciate[[:>:]]'; /* matches */

[[<:]] and [[>:]] are word boundaries. From the manual:

These markers stand for word boundaries. They match the beginning and end of words, respectively. A word is a sequence of word characters that is not preceded by or followed by word characters. A word character is an alphanumeric character in the alnum class or an underscore (_).

Edit: just to clarify, this also deals with situations where there’s a newline character after the word, or a comma, etc