Question

I am running a competition which is based on WP Custom Fields. I am trying to count all meta values of a meta_key=’odd’ for a specific user. I am using the formula below but it’s not returning any result.

$meta_key = 'odd';
$post_author = 'Admin';
$odd = $wpdb->get_var( $wpdb->prepare(
    "
    SELECT Count(meta_value)
    FROM $wpdb->postmeta
    INNER JOIN $wpdb->posts ON $wpdb->postmeta->post_id = $wpdb->posts->ID
    WHERE $wpdb->postmeta->meta_key = 'odd' AND $wpdb->posts->post_author = 'Admin'
    ",
    $meta_key, $post_author
) );
echo "<p>Total odd {$odd}</p>";

Anyone can help me? Thanks in advance.

Answer 1

You are mixing up the $wpdb variables and the $post variables – for your JOIN, for example, you can’t use $wpdb->postmeta->post_id, it would be {$wpdb->postmeta}.post_id, and would be even better to just use table aliases. Your prepare() is also not passing in your meta_key or author because you don’t have %s placeholders for them

$odd = $wpdb->get_var( $wpdb->prepare(
    "
    SELECT count(meta_value)
    FROM {$wpdb->postmeta} pm
    INNER JOIN {$wpdb->posts} p ON pm.post_id = p.ID
    WHERE pm.meta_key = %s AND p.post_author = %s
    ",
    $meta_key, $post_author
) );