一對一關系 1：1 @ToOne

@Entity
public class Order {
    @Id private Long id;

    private long customerId;

    @ToOne(joinProperty = "customerId")
    private Customer customer;
}

@Entity
public class Customer {
    @Id private Long id;
}

一對多 1:N @ToMany

@Entity
public class Customer {
    @Id private Long id;
 
    @ToMany(referencedJoinProperty = "customerId")
    @OrderBy("date ASC")
    private List<Order> orders;
}
 
@Entity
public class Order {
    @Id private Long id;
    private Date date;
    private long customerId;
}

referencedJoinProperty 應該只能是id,如果采用其他字段作為外鍵就不能用這個了屋厘。
joinProperties參數(shù)：對于更復雜的關系狰域，您可以指定@JoinProperty注釋列表度气。每個@JoinProperty都需要原始實體中的source屬性和目標實體中的引用屬性狰右。

@Entity
public class Customer {
    @Id private Long id;
    @Unique private String tag;
 
    @ToMany(joinProperties = {
            @JoinProperty(name = "tag", referencedName = "customerTag")
    })
    @OrderBy("date ASC")
    private List<Site> orders;
}
 
@Entity
public class Order {
    @Id private Long id;
    private Date date;
    @NotNull private String customerTag;
}

多對多 n：m @ToMany
使用@JoinEntity 注解 +中間表的形式

@Entity
public class Product {

    @Id
    private Long  id;
    private String name;

    @ToMany
    @JoinEntity(entity =JoinProductsWithOrders.class,sourceProperty = "productId",targetProperty = "orderId")
    private List<Order>  orders;
}

@Entity
public class Order {

    @Id
    private  Long id;

    private String  name;

    @ToMany
    @JoinEntity(entity = JoinProductsWithOrders.class,sourceProperty = "orderId",targetProperty = "productId")
    private List<Product>  products;
}

@Entity
public class JoinProductsWithOrders {

    @Id
    private Long id;
    private  Long   productId;
    private  Long   orderId;
}

build 后即可招驴，不會生成setProduts setOrders锁荔。
同時雙方不直接持有對方的字段锌畸。通過中間表的形式。

  Product  product =new Product();
        product.setId(1l);
        product.setName("衣服");
        EntityManager.getInstance().getProductDao().insert(product);

        Product  product1 =new Product();
        product1.setId(2l);
        product1.setName("褲子");
        EntityManager.getInstance().getProductDao().insert(product1);

        Order  order =new Order();
        order.setId(1l);
        order.setName("訂單1");
        EntityManager.getInstance().getOrderDao().insert(order);

        Order  order1 =new Order();
        order1.setId(2l);
        order1.setName("訂單2");
        EntityManager.getInstance().getOrderDao().insert(order1);

       //訂單1包含商品1随夸，商品2 
        JoinProductsWithOrders  jw =new JoinProductsWithOrders();
        jw.setOrderId(1l);
        jw.setProductId(1l);
        EntityManager.getInstance().getJoinProductsWithOrders().insert(jw);


        JoinProductsWithOrders  jws =new JoinProductsWithOrders();
        jws.setOrderId(1l);
        jws.setProductId(2l);
        EntityManager.getInstance().getJoinProductsWithOrders().insert(jws);

        //訂單2 包含 商品1九默，商品2
        JoinProductsWithOrders jw1 =new JoinProductsWithOrders();
        jw1.setOrderId(2l);
        jw1.setProductId(1l);
        EntityManager.getInstance().getJoinProductsWithOrders().insert(jw1);

        JoinProductsWithOrders jw1s =new JoinProductsWithOrders();
        jw1s.setOrderId(2l);
        jw1s.setProductId(2l);
        EntityManager.getInstance().getJoinProductsWithOrders().insert(jw1s);
       //經(jīng)過上面中間表的操作后，商品1宾毒，商品2分別再訂單1驼修，訂單2中了

 List<Order>  orders=  EntityManager.getInstance().getOrderDao().queryBuilder().list();
              for (Order  order:orders){
                  for (Product product:order.getProducts()){
                      Log.e("返回",product.getName()+"~~~"+product.getId());
                  }
              }

輸出：

08-07 16:48:34.944 13460-13460/com.green.dao E/返回: 訂單1
08-07 16:48:34.946 13460-13460/com.green.dao E/返回: 衣服~~~1
08-07 16:48:34.946 13460-13460/com.green.dao E/返回: 褲子~~~2
08-07 16:48:34.950 13460-13460/com.green.dao E/返回: 訂單2
08-07 16:48:34.951 13460-13460/com.green.dao E/返回: 衣服~~~1
08-07 16:48:34.951 13460-13460/com.green.dao E/返回: 褲子~~~2

官網(wǎng)：http://greenrobot.org/greendao/documentation/relations/