Use this window to associate a column in the new table being added with a column in one of the tables that is already part of your query.
Column in new-table
Click the drop-down and select the column from the table being added that will identify the related rows in this table.
Column in existing-table
Click the drop-down and select the column from the existing table that represents the same data value as the column you selected for the table being added.
Adds or updates the column relationship and dismisses this window.
Dismisses this window without adding or updating the column relationship.