如何使用hibernate从表中删除表引用在另一个表中的记录答案

【问题标题】：How to delete a record from a table the table reference is in another table using hibernate如何使用hibernate从表中删除表引用在另一个表中的记录
【发布时间】：2019-03-10 22:07:02
【问题描述】：

我是 Hibernate 的新手，我想对一个表执行删除，当前表引用到另一个表。

例如：Client_Loan 是我要删除的主表，另一个表是“Loan_Details”。 loan_details 表包含对 client_loan id 的 foreign_Key 引用。

我想对 client_loan 表执行删除，如果我删除 client_loan 表，另一个表中的引用也想使用 Hibernate 一次性删除，谁能告诉我如何执行。提前致谢。

【问题讨论】：

标签： postgresql hibernate

【解决方案1】：

首先从 Loan_Details 中删除，然后是 Client_loan

First delete from Loan_Details then Client_loan

int id = 2;
Session session=getSession();  
String hql = "delete from Loan_Details where client_loanid = :id"; 
session.createQuery(hql).setString("id", new Integer(id)).executeUpdate();

hql = "delete from Client_Loan where clientid = :id"; 
session.createQuery(hql).setString("id", new Integer(id)).executeUpdate();

【讨论】：

【解决方案2】：

You must be having classes like below

@Entity
@Table(name="Client_Loan")
public class ClientLoan {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String name;

    @OneToMany(cascade = CascadeType.ALL, 
        mappedBy = "client", orphanRemoval = true)
    private List<Loan_Details> loans = new ArrayList<>();

    public void setName(String name) {
        this.name = name;
    }

    public List<Loan_Details> getComments() {
        return loans;
    }

    public void addComment(Loan_Details loan) {
        loans.add(loan);
    }

}

below for load details

@Entity
@Table(name="Loan_Details ")
public class LoanDetails {


    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne
    private Client_Loan client;

    public void setPost(Client_Loan post) {
        this.post = post;
    }

    public String getReview() {
        return review;
    }

    public void setReview(String review) {
        this.review = review;
    }
}

Now in ClientLoan in OnetoMany mapping cascade = CascadeType.ALL
it means when you will delete CleintLoan all the LoanDetails will be deleted automatically

【讨论】：