Emp（一个员工对应一个部门）
package domain;
import java.sql.Date;
public class Emp {
//自有属性
private Integer empno;
private String ename;
private String job;
private Integer mgr;
private Date hiredate;
private Float sal;
private Float comm;
//为了通过员工 查询员工对应的部门信息 关联属性
private Dept dept;//(deptno dname loc)
public Emp() {
}
public Emp(Integer empno, String ename, String job, Integer mgr, Date hiredate, Float sal, Float comm, Dept dept) {
this.empno = empno;
this.ename = ename;
this.job = job;
this.mgr = mgr;
this.hiredate = hiredate;
this.sal = sal;
this.comm = comm;
this.dept = dept;
}
@Override
public String toString() {
return "Emp{" +
"empno=" + empno +
", ename='" + ename + '\'' +
", job='" + job + '\'' +
", mgr=" + mgr +
", hiredate=" + hiredate +
", sal=" + sal +
", comm=" + comm +
", dept=" + dept +
'}';
}
public Integer getEmpno() {
return empno;
}
public void setEmpno(Integer empno) {
this.empno = empno;
}
public String getEname() {
return ename;
}
public void setEname(String ename) {
this.ename = ename;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
public Integer getMgr() {
return mgr;
}
public void setMgr(Integer mgr) {
this.mgr = mgr;
}
public Date getHiredate() {
return hiredate;
}
public void setHiredate(Date hiredate) {
this.hiredate = hiredate;
}
public Float getSal() {
return sal;
}
public void setSal(Float sal) {
this.sal = sal;
}
public Float getComm() {
return comm;
}
public void setComm(Float comm) {
this.comm = comm;
}
public Dept getDept() {
return dept;
}
public void setDept(Dept dept) {
this.dept = dept;
}
}
Dept（一个部门下有多个员工）
public class Dept {
//自有属性
private Integer deptno;
private String dname;
private String loc;
//为了通过部门查询到 部门中的所有员工 关联属性
private List<Emp> empList;
public Dept() {
}
public Dept(Integer deptno, String dname, String loc, List<Emp> empList) {
this.deptno = deptno;
this.dname = dname;
this.loc = loc;
this.empList = empList;
}
@Override
public String toString() {
return "Dept{" +
"deptno=" + deptno +
", dname='" + dname + '\'' +
", loc='" + loc + '\'' +
", empList=" + empList +
'}';
}
public Integer getDeptno() {
return deptno;
}
public void setDeptno(Integer deptno) {
this.deptno = deptno;
}
public String getDname() {
return dname;
}
public void setDname(String dname) {
this.dname = dname;
}
public String getLoc() {
return loc;
}
public void setLoc(String loc) {
this.loc = loc;
}
public List<Emp> getEmpList() {
return empList;
}
public void setEmpList(List<Emp> empList) {
this.empList = empList;
}
}
EmpDao
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.mapping.FetchType;
import java.util.List;
public interface EmpDao {
//设计一个方法 根据员工empno编号 查询员工信息+所属部门信息
@Results(
id="selectEmp",
value={
@Result(property="empno",column="empno",id=true),
@Result(property="ename",column="ename"),
@Result(property="job",column="job"),
@Result(property="mgr",column="mgr"),
@Result(property="hiredate",column="hiredate"),
@Result(property="sal",column="sal"),
@Result(property="comm",column="comm"),
@Result(property="dept",javaType=Dept.class,column="deptno",one=@One(select="selectDept",fetchType=FetchType.LAZY))
})
@Select("select * from emp where empno = #{empno}")
public Emp selectOne(Integer empno);
//辅助方法
@Select("select * from dept where deptno = #{deptno}")
public Dept selectDept(Integer deptno);
//====================================================
//查询所有的emp信息+每个emp对应的dept对象
@Select("select * from emp") //会通过辅助方法public Dept selectDept(Integer deptno);查询多次
@ResultMap("selectEmp") //结果集存放方式会调用上面的@Results
public List<Emp> selectAll();
}
DeptDao
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.mapping.FetchType;
import java.util.List;
public interface DeptDao {
//设计一个方法 根据部门编号deptno 查询部门的信息+所属于当前部门的所有员工信息
@Results(
id="selectDept",
value={
@Result(property="deptno",column="deptno",id=true),
@Result(property="dname",column="dname"),
@Result(property="loc",column="loc"),
@Result(property="empList",javaType=List.class,column="deptno",many=@Many(select="selectEmp",fetchType=FetchType.LAZY)),
}
)
@Select("select * from dept where deptno = #{deptno}")
public Dept selectOne(Integer deptno);
//辅助方法
@Select("select * from emp where deptno = #{deptno}")
public Emp selectEmp(Integer deptno);
//==========================================================
@Select("select * from dept") //通过多次调用 public Emp selectEmp(Integer deptno);为dept中的empList赋值
@ResultMap("selectDept") //结果集存放方式会调用上面的@Results
public List<Dept> selectAll();
}
EmpService
public class EmpService {
private EmpDao dao = MyUtil.getMapper(EmpDao.class,true);
//设计一个业务方法 根据给定的员工empno编号 查询员工的信息+所属的部门信息
public Emp selectOne(Integer empno){
return dao.selectOne(empno);
}
//设计一个业务方法 查询表格中全部的emp信息+每个员工所属的部门信息
public List<Emp> selectAll(){
return dao.selectAll();
}
}
DeptService
public class DeptService {
private DeptDao dao = MyUtil.getMapper(DeptDao.class,true);
//设计一个业务方法 给定部门编号 查询部门信息+所属于当前部门的所有员工信息
public Dept selectOne(Integer deptno){
return dao.selectOne(deptno);
}
//设计一个业务方法 查询全部的部门信息+每个部门中的所有员工信息
public List<Dept> selectAll(){
return dao.selectAll();
}
}
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