Custom filter function not working with Custom post type

Question

I have custom post type "soto_property". I have made a custom filter to filter post listing according to used meta data named "operations". Here is my code-

<?php
add_filter( 'parse_query', 'soto_posts_filter' );
add_action( 'restrict_manage_posts', 'soto_posts_filter_restrict_manage_posts' );

function soto_posts_filter( $query )
{
    global $pagenow;
    if( is_admin() AND $query->query['post_type'] == 'soto_property' ) {
        $qv = &$query->query_vars;
        $qv['meta_query'] = array();

        if( !empty( $_GET['operations'] ) ) {
          $qv['meta_query'][] = array(
            'field' => 'operations',
            'value' => $_GET['operations'],
            'compare' => 'LIKE',
          );
        }

    }
}

function soto_posts_filter_restrict_manage_posts()
{
    global $wpdb;
    if($_GET['post_type']=='soto_property')
    {
        $sql = 'SELECT DISTINCT meta_key FROM '.$wpdb->postmeta.' where meta_key="operations" ORDER BY 1';
        $fields = $wpdb->get_results($sql, ARRAY_N);

 ?>
<select name="operations" id="filter-operations" class="custom-filter" style="display:none; width: 15%;" >
        <option value=""></option>
        <option value="2" <?php echo $_GET['operations']==2?"selected='selected'":'' ?>>Rent</option>
        <option value="1" <?php echo $_GET['operations']==1?"selected='selected'":'' ?>>Sale</option>
      </select>
<?php
    }
}

But my post are not filtering according to meta data "operations". This meta data is stored in wp_postmeta table in DB with meta_key=operation and meta_value=1 or meta_value=2 .

Can anyone help me.

Answer 1

Multiple things are wrong with your code:

1. You should never use values you get from a user ( $_GET , $_POST or $_REQUEST ) without sanitizing them. You should read this: Validating Sanitizing and Escaping User Data .
2. Your Select statement in the function soto_posts_filter_restrict_manage_posts is useless as you do not do anything with it. Also, your <select> code suggests that only one value can be used so why use DISTINCT ? Also, Shouldn't that statement link to the post ID ?

This is surely why you don't get the results you are expecting. I would suggest you add some var_dump here and there and validate each steps in your process to make sure you have the expected outcome all the way.