Question

I have a MySQL column ‘public’ that contains boolean values (aka tinyint, 1 or 0). When querying I generally don’t care about the value of the public column, so by default I pass an underscore (MySQL wildcard). In some instances though I only want rows that match “public = 0” or “public = 1” so I override the underscore with either 0 or 1. That’s not the clearest explanation I’ve ever given so here’s some code:

public function get_hunts($public = '_') {
  $sth = $this->_db->prepare("SELECT * FROM hunts WHERE( user_id = :user AND public = :public)");
  $sth->bindParam(':user', $this->_id);
  $sth->bindParam(':public', $public);
  $sth->execute();
  $result = $sth->fetchAll(PDO::FETCH_ASSOC);

  return $result;
}

//get any result
get_results();

//get only public results
get_hunts(1)

Binding an underscore (I’ve also tried the general wildcard %) in this way causes the query to fail. What is a better way of achieving this?

Answer 1

To use any wildcard characters, you’d need to use a LIKE comparison instead of an equals

AND public LIKE :public

Otherwise, you’d need to take some kind of query builder approach where you build up the WHERE conditions based on arguments to your function.

public function get_hunts($public = null) {
    $where = array(
        'user_id = :user'
    );
    $params = array(
        ':user' => $this->_id
    );

    if (null !== $public) {
        $where[] = 'public = :public';
        $params[':public'] = (boolean) $public;
    }

    $query = 'SELECT * FROM hunts WHERE ' . implode(' AND ', $where);
    $sth = $this->_db->prepare($query);
    $sth->execute($params); // same as binding

    return $sth->fetchAll(PDO::FETCH_ASSOC);
}