SSM整合篇】四. SSM整合 级联查询 基于【SSM整合篇】三

其他 2020-01-25 17:12:48 阅读次数: 0

SSM整合 级联查询 基于【SSM整合篇】三

github源码(day57-cascade) https://github.com/1196557363/ideaMavenProject

项目准备

  1. 本项目基于 【SSM整合篇】 三
    SSM整合篇】三. SSM整合+事务+单元测试案例 第一章（共四章）https://blog.csdn.net/TheNew_One/article/details/103888883
    SSM整合篇】三. SSM整合+事务+单元测试案例 第二章（共四章）https://blog.csdn.net/TheNew_One/article/details/103896990
    SSM整合篇】三. SSM整合+事务+单元测试案例 第三章（共四章）https://blog.csdn.net/TheNew_One/article/details/103897975
    SSM整合篇】三. SSM整合+事务+单元测试案例 完结 （共四章）https://blog.csdn.net/TheNew_One/article/details/103898570

  2. 新建项目day57-cascade并将上一天的项目的代码资源文件全部拿过来。
    在这里插入图片描述

  3. 删除User对象，用于测试事务的，在该案例用不到。

  4. mysql我这里还是用day56-ssm-transaction

  5. 加个log4j.properties 日志配置文件

#是日志记录的优先级，分为OFF、FATAL、ERROR、WARN、INFO、DEBUG、ALL或
log4j.rootLogger = debug,stdout,E,MAIL

log4j.appender.stdout=org.apache.log4j.ConsoleAppender  
log4j.appender.stdout.Target=System.out  
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout  
log4j.appender.stdout.Encoding=UTF-8
log4j.appender.stdout.layout.ConversionPattern= %d{yyy-MM-dd HH\:mm\:ss} %p %c{0}\:%L - %m%n

1. 查询所有部门

1.1 写dao，mapper，service及其impl

1.1.1 IDeptDao

package com.wpj.dao;

import com.wpj.bean.*;

import java.util.*;

/**
 * ClassName: IDeptDao
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 19:12
 * @since JDK 1.8
 */
public interface IDeptDao {
    /**
     * 获取所有的部门
     * @return
     */
    List<Dept> getAllDept();
}

1.1.2 IDeptDao.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wpj.dao.IDeptDao">
    <resultMap id="deptMap" type="dept">
        <id property="deptId" column="dept_id" />
        <result property="deptName" column="dept_name" />
        <result property="deptAddr" column="dept_addr" />
    </resultMap>
	<!-- 获取所有的部门 -->
    <select id="getAllDept" resultMap="deptMap">
        select * from dept
    </select>
</mapper>

1.1.3 IDeptService

package com.wpj.service;

import com.wpj.bean.*;
import org.springframework.stereotype.*;

import java.util.*;

/**
 * ClassName: IDeptService
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 19:46
 * @since JDK 1.8
 */
public interface IDeptService {
    /**
     * 获取所有的部门
     * @return
     */
    List<Dept> getAllDept();
}

1.1.4 DeptServiceImpl

package com.wpj.service.impl;

import com.wpj.bean.*;
import com.wpj.dao.*;
import com.wpj.service.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;

import java.util.*;

/**
 * ClassName: DeptServiceImpl
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 20:00
 * @since JDK 1.8
 */
@Service
public class DeptServiceImpl implements IDeptService {
    @Autowired
    private IDeptDao iDeptDao;
    
    public List<Dept> getAllDept() {
        return iDeptDao.getAllDept();
    }
}

1.2 写controller

package com.wpj.web.controller;

import com.wpj.bean.*;
import com.wpj.service.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;
import org.springframework.ui.*;
import org.springframework.web.bind.annotation.*;

import java.util.*;

/**
 * ClassName: DeptController
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\9 0009 11:55
 * @since JDK 1.8
 */
@Controller
@RequestMapping("/dept")
public class DeptController {
    @Autowired
    private IDeptService iDeptService;

    @RequestMapping("getAllDept")
    public String getAllDept(ModelMap map){

        List<Dept> deptList = iDeptService.getAllDept();
        map.put("deptList",deptList);

        return "deptList";
    }
}

1.2 创建deptList.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <table>
        <tr>
            <td>id</td>
            <td>name</td>
            <td>address</td>
        </tr>
        <tr th:each="dept:${deptList}">
            <td th:text="${dept.deptId}"></td>
            <td th:text="${dept.deptName}"></td>
            <td th:text="${dept.deptAddr}"></td>
        </tr>
    </table>
</body>
</html>

1.4 运行

http://localhost:8080/dept/getAllDept

1.5 结果

在这里插入图片描述

2. 根据查询来的部门查询该部门的员工

2.1 修改dept.html的部门为超链接

<tr th:each="dept:${deptList}">
	<td th:text="${dept.deptId}" />
	<td>
		<a th:text="${dept.deptName}" th:href="|emp/getEmpByDeptId/${dept.deptId}|" />
	</td>
	<td th:text="${dept.deptAddr}" />
</tr>

2.2 写dao，mapper，service及其impl

2.2.1 IEmpDao 定义getEmpByDeptId方法

package com.wpj.dao;

import com.wpj.bean.*;
import org.apache.ibatis.annotations.*;

import java.util.*;

/**
 * ClassName: IEmpDao
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 19:11
 * @since JDK 1.8
 */
public interface IEmpDao {
    /**
     * 获取所有的Emp
     * @return
     */
    List<Emp> getAllEmp();
    /**
     * 根据部门ID获取该部门下所有员工
     * @return
     */
    List<Emp> getEmpByDeptId(@Param("deptId") Integer deptId);
}

2.2.2 IEmpDao.xml 映射getEmpByDeptId

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wpj.dao.IEmpDao">
        <resultMap id="empMap" type="emp">
                <id property="empId" column="emp_id"/>
                <result property="empName" column="emp_name" />
                <result property="job" column="job" />
                <result property="superId" column="super_id" />
                <result property="deptNo" column="dept_no" />
        </resultMap>

        <select id="getEmpByDeptId" resultMap="empMap">
                select * from emp where dept_no = #{deptId}
        </select>
</mapper>

2.2.3 IEmpService

package com.wpj.service;

import com.wpj.bean.*;
import org.apache.ibatis.annotations.*;

import java.util.*;

/**
 * ClassName: IEmpService
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 19:47
 * @since JDK 1.8
 */
public interface IEmpService {

    /**
     * 根据部门ID获取该部门下所有员工
     * @return
     */
    List<Emp> getEmpByDeptId(Integer deptId);
}

2.2.4 IEmpServiceImpl

package com.wpj.service.impl;

import com.wpj.bean.*;
import com.wpj.dao.*;
import com.wpj.service.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;

import java.util.*;

/**
 * ClassName: EmpServiceImpl
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 20:03
 * @since JDK 1.8
 */
@Service
public class EmpServiceImpl implements IEmpService {
    @Autowired
    private IEmpDao iEmpDao;

    public List<Emp> getEmpByDeptId(Integer deptId) {
        return iEmpDao.getEmpByDeptId(deptId);
    }
}

2.3 写controller

package com.wpj.web.controller;

import com.wpj.bean.*;
import com.wpj.service.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;
import org.springframework.ui.*;
import org.springframework.validation.annotation.*;
import org.springframework.web.bind.annotation.*;

import java.util.*;

/**
 * ClassName: Controller
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 21:55
 * @since JDK 1.8
 */
@Controller
@RequestMapping("/emp")
public class EmpController {

    @Autowired
    private IEmpService iEmpService;
    
    @RequestMapping("/getEmpByDeptId/{deptId}")
    public String getEmpByDeptId(@PathVariable Integer deptId,ModelMap map){
        List<Emp> empList = iEmpService.getEmpByDeptId(deptId);
        map.put("empList",empList);
        return "empList";
    }

}

2.4 创建empList.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <base th:href="${#request.getContextPath()+'/'}">
</head>
<table>
    <tr>
        <td>id</td>
        <td>name</td>
        <td>job</td>
        <td>superId</td>
        <td>deptNo</td>
        <td>operation</td>
    </tr>
    <tr th:each="emp:${empList}">
        <td th:text="${emp.empId}" />
        <td th:text="${emp.empName}" />
        <td th:text="${emp.job}" />
        <td th:text="${emp.superId}" />
        <td th:text="${emp.deptNo}" />
        <td>
            <a href="#">编辑</a>
            <a href="#">删除</a>
        </td>
    </tr>
</table>
</body>
</html>

2.5 运行

在这里插入图片描述

2.6 结果

在这里插入图片描述
在这里插入图片描述

3. 关联查询Emp在这里插入图片描述

3.1 修改实体类Emp

添加2个对象属性并提供无参,全参,getter,setter和toString()

package com.wpj.bean;
/**
 * ClassName: Emp
 * Description:
 *      提供无参,全参,getter,setter和toString()
 * @author JieKaMi
 * @version 1.0
 * @date: 2020\1\8 0008 19:07
 * @since JDK 1.8
 */
public class Emp {
    private Integer empId;
    private String empName;
    private String job;
    // 领导id
    private Integer superId;
    // 领导对象
    private Emp superEmp;
    // 部门id
    private Integer deptNo;
    // 部门对象
    private Dept dept;
    public Emp() {}
    public Emp(Integer empId, String empName, String job, Integer superId, Integer deptNo) {
        this.empId = empId;
        this.empName = empName;
        this.job = job;
        this.superId = superId;
        this.deptNo = deptNo;
    }
    public Emp(Integer empId, String empName, String job, Integer superId, Emp superEmp, Integer deptNo, Dept dept) {
        this.empId = empId;
        this.empName = empName;
        this.job = job;
        this.superId = superId;
        this.superEmp = superEmp;
        this.deptNo = deptNo;
        this.dept = dept;
    }
    public Integer getEmpId() { return empId; }
    public void setEmpId(Integer empId) { this.empId = empId; }
    public String getEmpName() { return empName; }
    public void setEmpName(String empName) { this.empName = empName; }
    public String getJob() { return job; }
    public void setJob(String job) { this.job = job; }
    public Integer getSuperId() { return superId; }
    public void setSuperId(Integer superId) { this.superId = superId; }
    public Integer getDeptNo() { return deptNo; }
    public void setDeptNo(Integer deptNo) { this.deptNo = deptNo; }
    public Emp getSuperEmp() { return superEmp; }
    public void setSuperEmp(Emp superEmp) { this.superEmp = superEmp; }
    public Dept getDept() { return dept; }
    public void setDept(Dept dept) { this.dept = dept; }
    @Override
    public String toString() {
        return "Emp{" +
                "empId=" + empId +
                ", empName='" + empName + '\'' +
                ", job='" + job + '\'' +
                ", superId=" + superId +
                ", superEmp=" + superEmp +
                ", deptNo=" + deptNo +
                ", dept=" + dept +
                '}';
    }
}

3.2 修改mapper及其里面的<resultMap>

<?xml version="1.0" encoding="UTF-8" ?>
        <!DOCTYPE mapper
                PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
                "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.wpj.dao.IEmpDao">
        <resultMap id="empMap" type="emp">
                <id property="empId" column="emp_id"/>
                <result property="empName" column="emp_name" />
                <result property="job" column="job" />
                <result property="superId" column="super_id" />
                <result property="deptNo" column="dept_no" />
                <association property="superEmp" javaType="emp">
                        <result property="empName" column="superName" />
                </association>
        </resultMap>

        <select id="getEmpByDeptId" resultMap="empMap">
               SELECT
                    e1.*, e2.emp_name AS superName
                FROM
                    emp e1
                LEFT JOIN emp e2 ON (e1.super_id = e2.emp_id)
                WHERE
                    e1.dept_no =  #{deptId}
        </select>
</mapper>

3.2 修改IEmpList.html

添加一行td 显示领导名字

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <base th:href="${#request.getContextPath()+'/'}">
</head>
<table>
    <tr>
        <td>id</td>
        <td>name</td>
        <td>job</td>
        <td>superId</td>
        <td>superName</td>
        <td>deptNo</td>
        <td>operation</td>
    </tr>
    <tr th:each="emp:${empList}">
        <td th:text="${emp.empId}" />
        <td th:text="${emp.empName}" />
        <td th:text="${emp.job}" />
        <td th:text="${emp.superId}" />
      	<!-- 如果该员工就是最上级 即没有领导就进行判断 -->
        <td th:text="${emp.superEmp !=null?emp.superEmp.empName:''}" />
        <td th:text="${emp.deptNo}" />
        <td>
            <a href="#">编辑</a>
            <a href="#">删除</a>
        </td>
    </tr>
</table>
</body>
</html>

3.3 结果

在这里插入图片描述

依样画葫芦，将对应部门的名称给写出来（这里就不演示，可以去看源码，在文章头部有github的路径）

杰KaMi
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