How to filter my search in post if contains a word in title, content or excerpt?

Question

I'm trying to filter one search, and I'm interested in know if a word is inside the title, the content or the excerpt but without luck and finally I'm stucked.

$args = array(
            'post_type' => 'post',
            'posts_per_page' => '-1',
            'search_prod_title' => $_POST['wordToSearch'],
            'post_status' => 'publish',
            'orderby'     => 'title',
            'order'       => 'ASC'
        );

    add_filter( 'posts_where', 'title_filter', 10, 2 );
    add_filter( 'posts_where', 'content_filter', 10, 2 );
    add_filter( 'posts_where', 'excerpt_filter', 10, 2 );
    $posts = new WP_Query($args);
    remove_filter( 'posts_where', 'title_filter', 10, 2 );
    remove_filter( 'posts_where', 'content_filter', 10, 2 );
    remove_filter( 'posts_where', 'excerpt_filter', 10, 2 );

And my filter functions are those ones:

    function title_filter( $where, &$wp_query )
    {
        global $wpdb;
        if ( $search_term = $wp_query->get( 'search_prod_title' ) ) {
            $where .= ' AND ' . $wpdb->posts . '.post_title LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\'';
        }
        return $where;
    }

    function content_filter( $where, &$wp_query )
    {
        global $wpdb;
        if ( $search_term = $wp_query->get( 'search_prod_content' ) ) {
            $where .= ' AND ' . $wpdb->posts . '.post_content LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\'';
        }
        return $where;
    }

    function excerpt_filter( $where, &$wp_query )
    {
        global $wpdb;
        if ( $search_term = $wp_query->get( 'search_prod_excerpt' ) ) {
            $where .= ' AND ' . $wpdb->posts . '.post_excerpt LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\'';
        }
        return $where;
    }

The point is, the first filter function is working properly, so I can search by title and the results are good, but the results for the rest of the filters are wrong or not working.

Answer 1

Well, for whoever went under the same question, I found the solution:

I've changed the filter and looks like this now:

add_filter( 'posts_where', 'general_filter', 10, 2 );
$posts = new WP_Query($args);
remove_filter( 'posts_where', 'general_filter', 10, 2 );

and the function...

function general_filter( $where, &$wp_query )
{
    global $wpdb;
    if ( $search_term = $wp_query->get( 'search_prod_title' ) ) {
        $where .= ' AND (' . $wpdb->posts . '.post_title LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\' OR ' . $wpdb->posts . ' .post_excerpt LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\' OR ' . $wpdb->posts . ' .post_content LIKE \'%' . esc_sql( like_escape( $search_term ) ) . '%\')';
    }
    return $where;
}

The error basically was that the entire query was wrong, so while debugging the variable $where I found the error and fix it. Hope this could help someone.