Versuchen Sie es unten:-
14 ist die Kategorie-ID
$request = $wpdb->prepare("SELECT * FROM $wpdb->posts
LEFT JOIN $wpdb->term_relationships ON($wpdb->posts.ID = $wpdb->term_relationships.object_id)
LEFT JOIN $wpdb->term_taxonomy ON($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
WHERE ($wpdb->term_taxonomy.term_id <> 14
AND $wpdb->term_taxonomy.taxonomy = 'category'
AND $wpdb->posts.post_type = 'post'
AND $wpdb->posts.post_status = 'publish'
AND post_title like '%$search%'
AND post_date >= '" . date('Y-m-d').")");