Searching from a mysql database based on a string in php -

i have string foo = "a,b". want search in mysql database user_id while comparing string likes field. likes field has data in format interest => c v d b. different characters seperated space. tried using result not upto mark. how can go it?

this code

select user_id users interest %foo%; 

mysql not support multiple keyword search in set field, should add or condition of each search keyword regexp if format interest like=> a,c,v,d,b can use find_in_set() function otherwise regexp provide exact search.

select user_id users  interest regexp '[[:<:]]a[[:>:]]' , interest regexp '[[:<:]]b[[:>:]]' 

this query search a , b in field not aa, bbax

like not support exact search.