| Defines a many-valued association with many-to-many multiplicity.
If the Collection is defined using generics to specify the element
type, the associated target entity class does not need to be
specified; otherwise it must be specified.
Every many-to-many association has two sides, the owning
side and the non-owning, or inverse, side. The join table is
specified on the owning side. If the association is bidirectional,
either side may be designated as the owning side.
The same annotation elements for the
OneToMany
annotation apply to the ManyToMany annotation.
Example 1:
In Customer class:
@ManyToMany
@JoinTable(name="CUST_PHONES")
public Set getPhones() { return phones; }
In PhoneNumber class:
@ManyToMany(mappedBy="phones")
public Set getCustomers() { return customers; }
Example 2:
In Customer class:
@ManyToMany(targetEntity=com.acme.PhoneNumber.class)
public Set getPhones() { return phones; }
In PhoneNumber class:
@ManyToMany(targetEntity=com.acme.Customer.class, mappedBy="phones")
public Set getCustomers() { return customers; }
Example 3:
In Customer class:
@ManyToMany
@JoinTable(name="CUST_PHONE",
joinColumns=
@JoinColumn(name="CUST_ID", referencedColumnName="ID"),
inverseJoinColumns=
@JoinColumn(name="PHONE_ID", referencedColumnName="ID")
)
public Set getPhones() { return phones; }
In PhoneNumberClass:
@ManyToMany(mappedBy="phones")
public Set getCustomers() { return customers; }
since:
Java Persistence 1.0 |