left outer join preserving unmatched rows from the first table
https://docs.oracle.com/javadb/10.8.3.0/ref/rrefsqlj18922.html
- INNER JOIN operation
Specifies a join between two tables with an explicit join clause.
- LEFT OUTER JOIN operation
Specifies a join between two tables with an explicit join clause, preserving unmatched rows from the first table.
- RIGHT OUTER JOIN operation
Specifies a join between two tables with an explicit join clause, preserving unmatched rows from the second table.
- CROSS JOIN operation
Specifies a join that produces the Cartesian product of two tables. It has no explicit join clause.
- NATURAL JOIN operation
Specifies an inner or outer join between two tables. It has no explicit join clause. Instead, one is created implicitly using the common columns from the two tables.
JOIN operations https://docs.oracle.com/javadb/10.8.3.0/ref/rrefsqlj29840.html