两个表相关联如何创建实体

• 创建表:

1. t_customer  

   -- Create table
   create table MISPPRD.T_CUSTOMER
   (
     CUSTOMER_ID     NUMBER(20) not null,
     ADDRESS         NUMBER(20)
   )
   -- Add comments to the table 
   comment on table MISPPRD.T_CUSTOMER
     is '客户信息表';
   -- Add comments to the columns 
   comment on column MISPPRD.T_CUSTOMER.CUSTOMER_ID
     is '客户ID';
   comment on column MISPPRD.T_CUSTOMER.ADDRESS
     is '地址';
   -- Create/Recreate primary, unique and foreign key constraints  
   
     alter table MISPPRD.T_CUSTOMER
     add constraint PK_T_CUSTOMER__CUSTOMER_ID primary key (CUSTOMER_ID)
     
     alter table MISPPRD.T_CUSTOMER
     add constraint FK_CUSTOMER__CURRENT_ADDRESS foreign key (ADDRESS)
     references MISPPRD.T_CUSTOMER_ADDRESS (ADDRESS_ID);
     

2. T_CUSTOMER_ADDRESS

   -- Create table
   create table MISPPRD.T_CUSTOMER_ADDRESS
   (
     ADDRESS_ID  NUMBER(20) not null,
     CUSTOMER_ID NUMBER(20) not null,
     DETAIL      VARCHAR2(511)
   )
   -- Add comments to the table 
   comment on table MISPPRD.T_CUSTOMER_ADDRESS
     is '客户地址信息表';
   -- Add comments to the columns 
   comment on column MISPPRD.T_CUSTOMER_ADDRESS.ADDRESS_ID
     is '地址ID';
   comment on column MISPPRD.T_CUSTOMER_ADDRESS.CUSTOMER_ID
     is '客户ID';
   comment on column MISPPRD.T_CUSTOMER_ADDRESS.DETAIL
     is '详细地址';
   -- Create/Recreate primary, unique and foreign key constraints 
     alter table MISPPRD.T_CUSTOMER_ADDRESS
     add constraint PK_T_CUSTOMER_ADDRESS__ID primary key (ADDRESS_ID)

   观察两个表的关联关系,易得 : t_customer与t_customer_address的关系为一对多,t_customer_address与t_customer的关系为多对一

• 创建实体: 

1.  CustomerAddress

@Entity
@Table(name = "T_CUSTOMER_ADDRESS")
@org.hibernate.annotations.Entity(dynamicInsert = true, dynamicUpdate = true)
public class CustomerAddress {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "customer_address_seq")
    @SequenceGenerator(name = "customer_address_seq", sequenceName = "SEQ_CUST_ADDRESS__ADDRESS_ID", allocationSize = 1)
    @Column(name = "ADDRESS_ID", nullable = false)
    private Long addressId;


    @ManyToOne(cascade = { CascadeType.REFRESH, CascadeType.PERSIST,
            CascadeType.MERGE }, optional = true)
    @JoinColumn(name = "CUSTOMER_ID")
    private Customer customer;

　　public Long getAddressId() {
        return addressId;
    }

    public void setAddressId(Long addressId) {
        this.addressId = addressId;
    }
　　public Customer getCustomer() {
        return customer;
    }

    public void setCustomer(Customer customer) {
        this.customer = customer;
    }
} 

• 2. Customer

@Entity
@Table(name = "T_CUSTOMER")
@org.hibernate.annotations.Entity(dynamicInsert = true, dynamicUpdate = true)
public class Customer {
　
　　 @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "customer_seq")
    @SequenceGenerator(name = "customer_seq", sequenceName = "SEQ_CUSTOMER__CUSTOMER_ID", allocationSize = 1)
    @Column(name = "CUSTOMER_ID", nullable = false)
    private Long customerId;

　　@OneToMany(cascade = { CascadeType.REFRESH, CascadeType.PERSIST,
            CascadeType.MERGE }, mappedBy = "customer")
    private List<CustomerAddress> address;

　　

　　public Long getCustomerId() {
        return customerId;
　　}

    　
　　public void setCustomerId(Long customerId) {     
　　　　this.customerId = customerId; 
　　}

　　public List<CustomerAddress> getAddress() {
        return address;
    }

    public void setAddress(List<CustomerAddress> address) {
        this.address = address;
    }
}