Hibernate with legacy DB schema and composite FKs and PKs

Question

I am having some trouble trying to find a solution for this and I think it may not be possible at all, but I'll still give it a try here. So lets pretend my legacy DB schema on MySQL with MyISAM (no FKs) has the following 2 tables:

TblOrder
ORDERID (INT)    PK
CUSTOMERID (INT) PK
REPID (INT)      PK
ISORDER (INT)    PK
other columns...

TblOrderPos
ORDERID (INT)    PK
POSITIONID (INT) PK
other columns

What would my annotations have to look like to allow TblOrder to have a Set of TblOrderPos (identyfied by ORDERID) and TblOrderPos a private TblOrder instance? I did create EmbeddedId objects for both tables and everytime I try to create a property with @ManyToOne or @OneToMany overriding @JoinColumns Hibernate complains that the number of PK columns does not match (well it cant).

I really hope somebody has an idea or if it's possible at all.

-----------update------------

On TblOrder

@OneToMany(mappedBy="shoporder")
@JoinColumn(name="ORDERID")
public List<Orderposition> getOrderpositions(){
    return this.positions;
}

public void setOrderPositions(List<Orderposition> positions){
    this.positions = positions;
}

On TblOrderPos

@ManyToOne
@JoinColumn(name="ORDERID")
public Shoporder getShoporder(){
    return this.shoporder;
}

public void setShoporder(Shoporder order){
    this.shoporder = order;
}

That's the error I keep getting: A Foreign key refering TblOrder from TblOrderPos has the wrong number of column. should be 4

score 1 · Answer 1 · answered Apr 11 '12 at 14:01

1

It's not recommended, but it's doable with composite-id:

http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/mapping.html

answered Apr 11 '12 at 14:01

duffymo

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Perhaps he was asking specifically about how to do that using annotations. – Alan Escreet Apr 11 '12 at 14:13
Yes, that would be helpful. If it's not possible with annotations, an XML example would help too. – Michael Apr 11 '12 at 14:17

score 0 · Answer 2 · edited May 23 '17 at 12:27

It is possible with annotations, because I've used such structures.

Have you properly used @ManyToOne annotation to link with table with composite PK? It should look like that:

@ManyToOne
    @JoinColumns({
        @JoinColumn(name = "WOJ_ID", referencedColumnName = "WOJ_ID"),
        @JoinColumn(name = "POW_NR", referencedColumnName = "POW_NR"),
        })

I'm using @IdClass annotation and provide classes for composite PK, some example is posted in my answer to other question: Why is my EmbeddedId in hibernate not working?

Hibernate with legacy DB schema and composite FKs and PKs

2 Answers2