Hello, I have two tables, say "tblParents" and "tblChildren" (Access 2010). They both have primary keys that are AutoNumber fields (say "ParentKey" and "ChildKey"). tblChildren carries ParentKey field as a Number, Long Integer.
There is a Relationship defined that LEFT JOIN's tblParents!ParentKey to tblChildren!ParentKey, as One-To-Many, all 3 options checked for Ref Integrity, Cascading Updates & Deletes.
I can start with a query with just tblChildren, printing most of the fields, for all records. No problems. But when I add tblParents to the query, and the JOIN is automatically created from the Relationship, I get the "Data type mismatch in criteria expression" error message, even if I don't throw down any fields from tblParents.
I have checked for missing or bad values in the key fields in both tables, and checked for orphans in tblChildren. Everything seems ok.