Set the JoinType to the type of Join desired.
JoinType "InnerJoin" returns only those rows that have a match. The final number of rows is equal to or less than the original number of left-side rows.
"LeftOuterJoin" returns all rows on the left side. Column values from the right side are added to the left side when there is a match. When there are multiple matching rows from the right side, those rows are also added to the output.
"FullOuterJoin" returns all rows from both sides, combining those rows that match.
"Union" concatenates all rows from both datasets together.