MyBatis 级联操作_mybatis 级联insert

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详细教程网络资源

关键在于练习 resultMap、association、collection 标签的使用

项目原代码

一对一 (student -> class)

student 包含个人基本信息和内嵌对象 classes。
在查询student时，需要联合 student表和classes表进行查询。

数据表

CREATE TABLE classes(
    id int not null primary key,
    name varchar(20)
);

insert into classes (id,name) values (1,"一班"),(2,"二班"),(3,"三班");

CREATE TABLE student(
    id int not null primary key auto_increment,
    name varchar(10),
    cid int,
    foreign key (cid) references classes(id)
);

insert into student (id, name, cid) 
    values (1,"KawYang",1),(2,"KawYang",2),(3,"张三",2),(4,"李四",3),(5,"Tom",3),(6,"Jary",3);

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实体类

• Classes类对象

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Classes{
    private int id;
    private String name;
}
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• Student类对象

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student{
    private int id;
    private String name;
    private Classes classes;
}

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Repository

编写数据库操作的接口

public interface IStudentRepository {
    /**
     * find by id
     * @param id
     * @return student
     */
    Student findById(int id);

    /**
     * find all
     * @return student list
     */
    List<Student> findAll();
}
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Mapper

mapper