Insert a record into foreign table in JPA

Question

I have entities from tables in database such as:

You see their relationship is one-to-many The IDDot in Dot is an identity column. The IDMS in MaSoDuThuong is an identity column. In normally, i can insert one record into two tables but in other page I need to insert a record into MaSoDuThuong table when i know the value of IDDot . Pls help me do!

Answer 1

Dot dot = entityManager.getReference(Dot.class, dotId);
MaSoDuThuong m = new MaSoDuThuong();
m.setDot(dot);
em.persist(m);

As simple as that.