Question

$genre = array(     'Action',     'Adventure',     'Fantasy' ); $selectGenre_sql = 'SELECT genreID FROM genres WHERE dbGenre = ?';  if ($stmt->prepare($selectGenre_sql)) {     // bind the query parameters     $stmt->bind_param('s', $genre);     // bind the results to variables     $stmt->bind_result($genres);     // execute the query     $stmt->execute();     $array1 = array();     while ($stmt->fetch()) {         $array1[] = $genres;     } } 

The code above gets the value from genreID when dbGenre is equal to $genre. And then store the results in an array. But it’s not working because $genre is an array, so I need to loop through it to get a different value from genreID each time.

The ‘genres’ table contains two columns: genreID (INT) and dbGenre (VARCHAR)

I just need each genreID (that is a number)… Let’s say when dbGenre is equal to Action, then store the genreID in an array1, and then loop the $genre array to get the genreID for the next value and store it again in array1.

How can I fix it?

Answer 1

You can’t bind an array to an SQL parameter. You can use a parameter in SQL in place of a single literal value. Not a list of values, or an expression, or a column name or table name.

To solve the task in your case, you can use either of two solutions:

First solution: loop over $genre array, bind each value one at a time and execute the SQL query for each value.

$stmt->prepare($selectGenre_sql); $genre = array(); foreach ($gengre as $genreID) {     $stmt->bind_param('s', $genreID);     $stmt->execute();     $stmt->bind_result($genres);     while ($stmt->fetch()) {         $genre[] = $genres;     } } 

Second solution: execute the query once, with multiple parameters, one for each value in the array. This requires some tricky code to build a variable number of ? placeholders in the SQL query, separated by commas.

$selectGenre_sql = 'SELECT genreID FROM genres WHERE dbGenre IN ('  . join(',', array_fill(0, count($genre), '?')) . ')'; 

Also you need to get tricky calling bind_param() with a variable number of arguments based on the elements in your $genre array:

$stmt->prepare($selectGenre_sql); $temp = array(); foreach ($genre as $key => $value) {     $temp[] = &$genre[$key]; }  array_unshift($genre, str_repeat('i', count($genre))); call_user_func_array(array($stmt, 'bind_param'), $genre);  $stmt->execute();  $stmt->bind_result($genres);  $array1 = array(); while ($stmt->fetch()) {     $array1[] = $genres; } 

You might want to consider using PDO_MYSQL because it’s easier to bind parameters from an array. The MySQLi interface is pretty awkward for this case.