有什么区别:
@Entity
public class Company {
@OneToMany(cascade = CascadeType.ALL , fetch = FetchType.LAZY)
@JoinColumn(name = "companyIdRef", referencedColumnName = "companyId")
private List<Branch> branches;
...
}
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和
@Entity
public class Company {
@OneToMany(cascade = CascadeType.ALL , fetch = FetchType.LAZY, mappedBy = "companyIdRef")
private List<Branch> branches;
...
}
Run Code Online (Sandbox Code Playgroud) 我想在 2 个实体、消费者和政策之间建立一对多关系。一个消费者应该有几个政策。
这是我想要的消费者 JSON 对象的示例:
{
id : 1,
name : "Peter",
endpoint: "123.456.778",
policies: [
{
id : 1,
name: "policy 01"
},
{
id : 2,
name: "policy 02"
}
]
}
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这是我到目前为止:
政策实体
@Entity
public class Policy {
@Id
@GeneratedValue
@Column(name = "id")
private Integer id;
@Column(name = "name")
private String name;
//getters and setters
}
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消费者实体
@Entity
public class Consumer {
@Id
@GeneratedValue
@Column(name = "consumer_id")
private Integer id;
@Column(name = "name")
private String name; …Run Code Online (Sandbox Code Playgroud)