WordPress database error: [Subquery returns more than 1 row]
update wp_1post_views_his htb set post_views_today = concat(concat(post_views_today,','),(select post_views_today from wp_1post_views tb where tb.post_id = htb.post_id AND tb.view_type = htb.view_type )) where htb.post_id!= 0 AND htb.year_id = 2019