Wordpress - 基于表单输入添加查询

Question

I have a form that essentially filters a query for courses. The form has multiple options but lets take 2 of those, whether the course is open and its location. The query fully programmed looks like this:

$query = array(
        'post_type' => 'courses',
            'meta_query' => array(
                'relation' => 'AND',
                    array(
                        'key' => 'course_location',
                        'compare' => '=',
                        'value' => 'Birmingham',
                    ),
                    array(
                        'key' => 'course_open',
                        'compare' => '=',
                        'value' => 1,
                    ),
            ),
        );

Now when I use the form this is the code I have...

Basic Start of query

 $query = array(
     'post_type' => 'courses',
 );

Adding in location from form:

if(isset($_GET['location']) && $_GET['location'] != '') {       
    $query['meta_query'] = array(
        'relation' => 'AND',
             array(
                'key' => 'course_location',
                'compare' => '=',
                'value' => $_GET['location'],
             ),
    );  
}

Adding in if the course is open:

if(isset($_GET['open']) && $_GET['open'] != '') {       
    $query['meta_query'] = array(
        'relation' => 'AND',
            array(
                'key' => 'course_open',
                'compare' => '=',
                'value' => $_GET['open'],
            ),
    );  
}

The problem I have is the course open will replace the course locations in the query. If I just set one of the options it works perfectly I just need to keep adding to the query if its set in the form. Any idea how I would do this?

Answer 1

Solved it!

So I changed the Open code to:

if(isset($_GET['open']) && $_GET['open'] != '') {       
    $open =
        array(
            'key' => 'course_open',
            'compare' => '=',
            'value' => $_GET['open'],
    );                      
}

The Location to:

if(isset($_GET['location']) && $_GET['location'] != '') {       
        $location = array(
            'key' => 'course_location',
            'compare' => '=',
            'value' => $_GET['location'],
        );              
 }

And the main query:

$query = array(
     'post_type' => 'courses',
         'meta_query' => array(
            'relation' => 'AND',
             $open,
             $location,
          ),
);