I am new to plugin development and I am working on one that adds posts from xml data. Each item from the xml contains two unique values (affiliate id and a product id) that I store as Meta Data along with the post.
However the feed updates once in a while, so now I need to figure a way to check if a value is present in the meta data of any of my posts. I need the id of that post in my plugin script to decide whether to create new post or update an existing post.
$querystr = "SELECT post_id, count(post_id)
(meta_key = 'product_aid' AND meta_value = '". $aid ."') OR
(meta_key = 'product_id' AND meta_value = '". (string)$item->productID ."')
GROUP BY post_id
HAVING count(post_id) = 2;
$postid = $wpdb->get_var($wpdb->prepare($querystr));