This is the fourth or fifth thread you have started for the same question. Creating new threads every day or so isn't going to get you more help. Keep the same question in one place. it keeps all the responses you do get together instead of fragmenting them across multiple threads.

We have tried to answer this for you before but I don't recall you ever answering the question about how you want to handle null values in either or both of the columns you are comparing. Without that informationi e really can't help you.