OneToMany Mapping

I faced this issue on August, let me explain you the situation, I had a Table called PURCHASE, with a 1:N Relationship with PURCHASE_MODULE and TRANSACTION tables

TRANSACTION >-----PURCHASE-----< PURCHASE_MODULE

First thing, How do I represent that using annotations (Hibernate): @Entity @Table(name = "PURCHASE") public class Purchase implements java.io.Serializable { @Id @Column(name = "ID", unique = true, nullable = false, insertable = true, updatable = true, precision = 10, scale = 0) public long getId() { return this.id; } ... @OneToMany(mappedBy="purchase", fetch=FetchType.LAZY) public List<Transaction> getTransactions() { return transactions; } @OneToMany(mappedBy="purchase", fetch=FetchType.LAZY) public List<PurchaseModule> getPurchaseModules() { return purchaseModules; } } @Entity @Table(name = "PURCHASE_MODULE") public class PurchaseModule implements java.io.Serializable { @ManyToOne(optional=false, fetch = FetchType.EAGER) @JoinColumn(name="PURCHASE_ID", referencedColumnName="id") private Purchase purchase; } @Entity @Table(name = "TRANSACTION") public class Transaction implements Serializable { @ManyToOne(optional=false, fetch = FetchType.EAGER) @JoinColumn(name="purchase_id", referencedColumnName="id") private Purchase purchase; }
Now what I want is each time I populate Purchase and set both List's (transactions and purchaseModules) and Invoke a SAVE for Purchase, the 3 tables will be impacted( there will be at least 3 INSERTs): purchaseDAO.save(purchase)
But this wasn't working as I expected, because no matter if I populated both ArrayList's (List) I never saw more than 1 Insert on my console.

Then the spark I was looking for! Inspiration came to me :P
On the Annotation @OneToMany there is an additional attribute I didn't include: cascade (The operations that must be cascaded to the target of the association)
@OneToMany(mappedBy="purchase", fetch=FetchType.LAZY, cascade=CascadeType.ALL) public List<Transaction> getTransactions() { return transactions; } @OneToMany(mappedBy="purchase", fetch=FetchType.LAZY, cascade=CascadeType.ALL) public List<PurchaseModule> getPurchaseModules() { return purchaseModules; }
On my case I don't care, so I just include ALL operations :P