Hibernate初学者---多对多单/双向关联

Hibernate 版本： v5.2.10
Eclipse版本：v4.7.1
JDK版本: v1.8
MySQL版本：v5.7

多对多单向

POJO类一

package com.bak.bum.union;import java.util.HashSet;import java.util.Set;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.JoinTable;import javax.persistence.ManyToMany;import javax.persistence.Table;@Entity@Table(name = "100_teacher")public class Teacher {    private int id;    private String name;    Set<Students> students = new HashSet<Students>();    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    public int getId() {        return id;    }    public String getName() {        return name;    }    @ManyToMany    @JoinTable(name = "tsTable", joinColumns = { @JoinColumn(name = "TeacherID") }, inverseJoinColumns = {            @JoinColumn(name = "StudentsID") })    public Set<Students> getStudents() {        return students;    }    public void setId(int id) {        this.id = id;    }    public void setName(String name) {        this.name = name;    }    public void setStudents(Set<Students> students) {        this.students = students;    }}

POJO类二

package com.bak.bum.union;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.Table;@Entity@Table(name="100_students")public class Students {    private int id;    private String name;    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    public int getId() {        return id;    }    public String getName() {        return name;    }    public void setId(int id) {        this.id = id;    }    public void setName(String name) {        this.name = name;    }}

Junit -TEST类

package com.bak.fan.test;import java.util.EnumSet;import org.hibernate.boot.Metadata;import org.hibernate.boot.MetadataSources;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;import org.hibernate.service.ServiceRegistry;import org.hibernate.tool.hbm2ddl.SchemaExport;import org.hibernate.tool.schema.TargetType;public class Test {    @org.junit.Test    public void test() {        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();        Metadata metadata = new MetadataSources(serviceRegistry).buildMetadata();        SchemaExport schemaExport = new SchemaExport();        schemaExport.create(EnumSet.of(TargetType.DATABASE), metadata);}}

hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>  <!DOCTYPE hibernate-configuration PUBLIC      "-//Hibernate/Hibernate Configuration DTD 3.0//EN"      "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><hibernate-configuration>    <session-factory>        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>        <property name="connection.username">root</property>        <property name="connection.password">shwythnn00</property>        <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>        <property name="show_sql">true</property>        <property name="hibernate.format_sql">true</property>        <property name="hibernate.hbm2ddl.auto">create</property>        <property name=""></property>        <mapping class="com.bak.bum.union.Teacher" />        <mapping class="com.bak.bum.union.Students" />    </session-factory></hibernate-configuration>  

输出结果

SHOW DB

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多对多双向

POJO类一

package com.bak.bum.union;import java.util.HashSet;import java.util.Set;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.JoinTable;import javax.persistence.ManyToMany;import javax.persistence.Table;@Entity@Table(name = "200_teacher")public class Teacher {    private int id;    private String name;    Set<Students> students = new HashSet<Students>();    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    public int getId() {        return id;    }    public String getName() {        return name;    }    @ManyToMany    @JoinTable(name = "tsTable", joinColumns = { @JoinColumn(name = "TeacherID") }, inverseJoinColumns = {            @JoinColumn(name = "StudentsID") })    public Set<Students> getStudents() {        return students;    }    public void setId(int id) {        this.id = id;    }    public void setName(String name) {        this.name = name;    }    public void setStudents(Set<Students> students) {        this.students = students;    }}

POJO类二

package com.bak.bum.union;import java.util.HashSet;import java.util.Set;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.ManyToMany;import javax.persistence.Table;@Entity@Table(name = "200_students")public class Students {    private int id;    private String name;    private Set<Teacher> teacher = new HashSet<Teacher>();    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    public int getId() {        return id;    }    public String getName() {        return name;    }    @ManyToMany(mappedBy="students")    public Set<Teacher> getTeacher() {        return teacher;    }    public void setId(int id) {        this.id = id;    }    public void setName(String name) {        this.name = name;    }    public void setTeacher(Set<Teacher> teacher) {        this.teacher = teacher;    }}

Junit-Test类

package com.bak.fan.test;import java.util.EnumSet;import org.hibernate.boot.Metadata;import org.hibernate.boot.MetadataSources;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;import org.hibernate.service.ServiceRegistry;import org.hibernate.tool.hbm2ddl.SchemaExport;import org.hibernate.tool.schema.TargetType;public class Test {    @org.junit.Test    public void test() {        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();        Metadata metadata = new MetadataSources(serviceRegistry).buildMetadata();        SchemaExport schemaExport = new SchemaExport();        schemaExport.create(EnumSet.of(TargetType.DATABASE), metadata);}}

hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>  <!DOCTYPE hibernate-configuration PUBLIC      "-//Hibernate/Hibernate Configuration DTD 3.0//EN"      "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><hibernate-configuration>    <session-factory>        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>        <property name="connection.username">root</property>        <property name="connection.password">shwythnn00</property>        <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>        <property name="show_sql">true</property>        <property name="hibernate.format_sql">true</property>        <property name="hibernate.hbm2ddl.auto">create</property>        <property name=""></property>        <mapping class="com.bak.bum.union.Teacher" />        <mapping class="com.bak.bum.union.Students" />    </session-factory></hibernate-configuration>  

输出结果

SHOW DB；

JAR

多对多单双向关联，对数据表无影响。只是在程序上可以互相访问。