使用Mybatis如何实现多对一或一对多的关联查询-创新互联

使用Mybatis 如何实现多对一或一对多的关联查询？针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。

首先  数据库量表之间字段关系（没有主外键）

studentmajor表的id字段对应student表里major字段

两个实体类

package com.model;
import java.util.Date;
public class Student {
  private Integer sno;
  private String sname;
  private String ssex;
  private Integer sclass;
  private StudentMajor studentmajor;
  public Student() {
    super();
  }
  public Student(Integer sno, String sname, String ssex, Integer sclass, StudentMajor studentmajor) {
    super();
    this.sno = sno;
    this.sname = sname;
    this.ssex = ssex;
    this.sclass = sclass;
    this.studentmajor = studentmajor;
  }
  public StudentMajor getStudentmajor() {
    return studentmajor;
  }
  public void setStudentmajor(StudentMajor studentmajor) {
    this.studentmajor = studentmajor;
  }
  public Integer getSno() {
    return sno;
  }
  public void setSno(Integer sno) {
    this.sno = sno;
  }
  public String getSname() {
    return sname;
  }
  public void setSname(String sname) {
    this.sname = sname;
  }
  public String getSsex() {
    return ssex;
  }
  public void setSsex(String ssex) {
    this.ssex = ssex;
  }
  @Override
  public String toString() {
    return "Student [sno=" + sno + ", sname=" + sname + ", ssex=" + ssex + ", sclass=" + sclass + ", studentmajor="
        + studentmajor + "]";
  }
  public Integer getSclass() {
    return sclass;
  }
  public void setSclass(Integer sclass) {
    this.sclass = sclass;
  }
}