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.
How can that be achieved?