How to delete a row in the connection table automatically to avoid a ConstraintViolationException?

Question

This seems to be a pretty simple question, or at least a simple answer. But - I'm really not a database guy, and I'm still pretty far from the Hibernate learning curve. However, here is the setting:

Consider a many-to-many unidirectional relationship between two objects: from Footo Bar:

^{(forgiving any typos below is obviously a simplification of the actual code)}

FooDTO.java:

@Entity
@Table(name = "MyDB.dbo.Foo")
class FooDTO implements Serializable
{
    private int id;
    private String name;
    private Set<BarDTO> bars = new HashSet<BarDTO>();

    ...

    @Fetch(FetchMode.JOIN)
    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "MyDB.dbo.FooBar",
               joinColumns = { @JoinColumn(name = "fooId") },
               inverseJoinColumns = { @JoinColumn(name = "barId") })
    public Set<BarDTO> getBars()
    {
        return bars;
    }
    public void setBars(Set<Bar> bars)
    {
        this.bars = bars;
    }
}

BarDTO.java:

@Entity
@Table(name = "MyDB.dbo.Bar")
class BarDTO implements Serializable
{
    private int id;
    private String name;

    ...
}

On the TSQL side, the connection table is configured as follows:

CREATE TABLE [dbo].[FooBar](
    [id] [int] NOT NULL IDENTITY PRIMARY KEY,
    [fooId] [int] NOT NULL,
    [barId] [int] NOT NULL,
    CONSTRAINT fk_FooBar_FooId FOREIGN KEY (fooId) REFERENCES [dbo].[Foo](id),
    CONSTRAINT fk_FooBar_BarId FOREIGN KEY (barId) REFERENCES [dbo].[Bar](id),
) ON [PRIMARY]
END

If I try to delete a BarDTO, I get a ConstraintViolationExceptionbecause I did not delete the first row in the connection table (duh).

Questions:

• Hibernate , Bar? ?
• , Foo, Bar, Bar Foo Bar s?

, , NamedQuery, API , , . , :

SELECT f FROM FooDTO f INNER JOIN ??? WHERE f.id = ???

, barId FooBar, . ( , - ?)

Answer 1

Hibernate , ? ?

BarDTO FooDTO, .

, Foos, , Foo Bars?

:

SELECT f FROM FooDTO f WHERE :bar MEMBER OF f.bars 

bar.getFoos().