php - Exploding string to array, then searching array for multiple results -

background

users on website can give profile 'keywords', each separated ', '. example:

green apples, bananas, red apples, pears

this stored in database string.

i have livesearch page users can search users keyword. on search, page suggests keywords user types. example, user may type:

apples

and page suggest

green apples, red apples.

method

when input sent keywordsearch.php, page searches following:

$search_string_w = '%'.$search_string.'%'; $stmt = $dbh->prepare('select `keywords` `users` `keywords` ?'); $stmt->execute(array($search_string_w)); while($results = $stmt->fetch(pdo::fetch_assoc)) {     $result_array[] = $results; } 

this gets row of user has keyword. however, want display each individual keyword search suggestions, if keyword appears multiple times.

if (isset($result_array)) {     foreach ($result_array $result) {         $keyw = explode(', ', $result['keywords']);         $keyk = array_search($search_string, $keyw); 

now, $keyw[$keyk] return single keyword. if search apples, return green apples , not red apples too.

question

how can alter code returns occurrences of searched term?

array_search() , array_keys() find apple given apple. preg_grep() give of entries containing apple such green apple.

the $result_array can searched follows preg_grep():

$keyw = explode(', ', $result['keywords']); //an array can implode or loop through $keyk = preg_grep("/$search_string/", $keyw); // case-insensitive use:  "/$search_string/i" 

ideally should have keywords table each keyword own row related user id.