Outer Join

Connections implemented through the JOIN/ON keywords uniformly use @Join for mapping.

This type of connection adds dynamic query conditions after the ON keyword. To achieve this, a new query object is introduced to map the conditions of the ON clause, and it is defined as a field of the main query object.

For this purpose, a new annotation @Join is designed to map the joined tables and specify the join type, while reusing the existing @ForeignKey annotation to map the join conditions.

LN	Class Definition	SQL Clauses
1	public class CustomerOrdersQuery extends PageQuery {
2	@Join(from = @View(value = CustomerEntity.class, alias = "c"),	FROM customer c
3	type = Join.JoinType.LEFT_JOIN,	LEFT JOIN orders o
4	join = @View(value = OrdersEntity.class, alias = "o"))	ON o.o_custkey = c.c_custkey
5	private JoinOrders joinOrders;	AND o.o_comment NOT LIKE ?
6	}