Question

I have a wordpress plugin that essentially creates a mysql query and returns the results to wordpress.

It is user driven and so can end up in large queries with multiple NOT LIKEs which results in a very slow query.

Any suggestions that I could use to improve:

SELECT field1,field2,field3,field4 
from datatable 
WHERE (title NOT LIKE '%word%' AND title NOT LIKE '%word2%'
AND title NOT LIKE '%word3%' AND title NOT LIKE '%word4%' 
AND title NOT LIKE '%word5%' AND title NOT LIKE '%word6%' 
AND title NOT LIKE '%word7%' AND title NOT LIKE '%word8%' 
AND title NOT LIKE '%word9%') 
AND MATCH (title) AGAINST ("\"brandname\" " IN BOOLEAN MODE) 
ORDER BY total ASC LIMIT 0,60

The customer is adding a lot of negative keywords to the wordpress plugin which results in larger queries than the one above.

Answer 1

This is most easily done with REGEXP. For multiple words, use a group like (one|two|three)

SELECT 
  field1,
  field2,
  field3,
  field4
from datatable
WHERE 
  title NOT REGEXP '(word1|word2|word3|word4|word5...|word9)'
  AND MATCH (title) AGAINST ("\"brandname\" " IN BOOLEAN MODE)
ORDER BY total ASC
LIMIT 0,60