1. Find the sale value for items ordered in 2012. Exclude the value of items which were returned.
2. All rows from both tables are returned in an INNER JOIN.
3. LEFT JOIN returns all rows from the left table, with the matching rows in the right table.
4. A LEFT JOIN or INNER JOIN creates a row each time the join criteria is satisfied, which can result in duplicate rows. One way to avoid this is to use data blending instead.
Be sure to click Submit Quiz to see your results!
