I also included the select query that works as needed until I use the WHERE clause with dates. Excuse my ignorance but not sure what else you mean.

You are correct. I did supply some sample data with expected results in my initial post - is there something else that would help?

it worked as was suggested - I had a typo. thanks for the suggestions 🙂

Since I'm new to this maybe another shot at explaining.

There are no empty records in the coitem_log table - every time a line item on a order is changed an...

There are no Null activity dates. I'm trying to match product codes that have no activity, essentially building that list through the query.