# Many-to-one mapping

Use a Many-to-One mapping to defines a single-valued association to another entity class that has many-to-one multiplicity.

1. In the JPA Structure view, select the field to map.

2. Right click the field and then select Map As > Many-to-One. The JPA Details view (for attributes) displays the properties for the selected.

   JPA Details, Many-to-one mapping

3. Complete each field in the Many-to-One Mapping area.

4. Complete the remaining areas in the JPA Details view (for attributes).

Eclipse adds the following annotations to the field:

    @JoinTable(joinColumns=@JoinColumn(name="<JOIN_COLUMN>"),
        name = "<JOIN_TABLE_NAME>")
    @ManyToOne(
        targetEntity=<TARGET_ENTITY>,
        fetch=<FETCH_TYPE>,
        =<_TYPE>
    )

Related tasks

- Mapping an entity

Related references

- JPA Structure view

- JPA Details view (for attributes)

- Joining Strategy

- Derived Identity

Related concepts

- Understanding OR mappings

- Understanding Java Persistence API