• hibernate 多对多 单向关联


    package com.bjsxt.hibernate;

    import java.util.HashSet;
    import java.util.Set;

    import javax.persistence.Embedded;
    import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    import javax.persistence.JoinColumn;
    import javax.persistence.JoinColumns;
    import javax.persistence.JoinTable;
    import javax.persistence.ManyToMany;
    import javax.persistence.ManyToOne;
    import javax.persistence.OneToOne;
    import javax.persistence.PrimaryKeyJoinColumn;
    import javax.persistence.Table;

    @Entity
    @Table(name="t_teacher")
    public class User {
    @Id
    @GeneratedValue
    private int id;
    private String name;
    @ManyToMany
    @JoinTable(name="t_teacher_student",joinColumns={@JoinColumn(name="teacher_Id")},inverseJoinColumns={@JoinColumn(name="student_Id")})

    // 这个地方的1jointable  是 两张表的中间表  name属性为当前中间表的名字,2joinColumns 里面的 joinColumn 的name 指的是 :中间表中对应teacher表的  字段

    起名叫teacher_Id ,3  inverseJoinColumn 指的是  另一个类表student 对应  中间表t_teacher_student的字段起名为student_Id;



    private Set<Group> students = new HashSet<Group>();

    public Set<Group> getStudents() {
    return students;
    }

    public void setStudents(Set<Group> students) {
    this.students = students;
    }

    public int getId() {
    return id;
    }

    public void setId(int id) {
    this.id = id;
    }
    public String getName() {
    return name;
    }
    public void setName(String name) {
    this.name = name;
    }
    ````````````````````````````````````````````````````````

    package com.bjsxt.hibernate;

    import java.util.HashSet;
    import java.util.Set;

    import javax.persistence.Embedded;
    import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    import javax.persistence.JoinColumn;
    import javax.persistence.JoinColumns;
    import javax.persistence.OneToMany;
    import javax.persistence.OneToOne;
    import javax.persistence.PrimaryKeyJoinColumn;
    import javax.persistence.Table;

    @Entity
    @Table(name="t_student")
    public class Group {
    @Id
    @GeneratedValue
    private int id;

    private String name;

    public int getId() {
    return id;
    }


    public void setId(int id) {
    this.id = id;
    }
    public String getName() {
    return name;
    }
    public void setName(String name) {
    this.name = name;
    }


    }




    }

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  • 原文地址:https://www.cnblogs.com/lize1215/p/7642326.html
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