使用mybatis完成增删改查的案例

案例：

1.在新创建的项目中调用jar包

2.创建实体类bean包，dao包，测试类test包

3.在com.wang.bean中创建实体类Emp

package com.wang.bean;

public class Emp {
    private Integer eid;
    private String ename;
    private String dept;
    private String job;
    private Integer sal;
    private String phone;
    private String address;

    @Override
    public String toString() {
        return "Emp{" +
                "eid=" + eid +
                ", ename='" + ename + '\'' +
                ", dept='" + dept + '\'' +
                ", job='" + job + '\'' +
                ", sal=" + sal +
                ", phone='" + phone + '\'' +
                ", address='" + address + '\'' +
                '}';
    }

    public Integer getEid() {
        return eid;
    }

    public void setEid(Integer eid) {
        this.eid = eid;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public String getDept() {
        return dept;
    }

    public void setDept(String dept) {
        this.dept = dept;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public Integer getSal() {
        return sal;
    }

    public void setSal(Integer sal) {
        this.sal = sal;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

4.在src里面创建mybatis.xml文件，在里面设置数据库连接

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="jdbc"></transactionManager>
            <dataSource type="pooled">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://127.0.0.1:3306/web1"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper class="com.wang.dao.EmpDao"></mapper>
    </mappers>
</configuration>

5.在com.wang.dao包中创建EmpDao接口类，在里面创建接口方法

package com.wang.dao;

import com.wang.bean.Emp;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface EmpDao {
    List<Emp> selectAll();
    Emp selectById(int eid);
    int addEmp(Emp emp);
    int reviseEmp(Emp emp);
    int delEmp(int eid);
    Emp dongtai(@Param("ename") String ename, @Param("dept") String dept, @Param("job") String job);
}

6.在com.wang.dao包中创建EmpDao.xml文件在里面设置映射和sql语句

<?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">
<!--namespace是映射的dao接口-->
<mapper namespace="com.wang.dao.EmpDao">
    <select id="selectAll" resultType="com.wang.bean.Emp">
        select*from emp;
    </select>
    <select id="selectById" resultType="com.wang.bean.Emp" parameterType="int">
        select*from emp where eid=#{eid};
    </select>
    <insert id="addEmp" parameterType="com.wang.bean.Emp">
        insert into emp(ename,dept,job,sal,phone,address) values(#{ename},#{dept},#{job},#{sal},#{phone},#{address})
    </insert>
    <update id="reviseEmp" parameterType="com.wang.bean.Emp">
        update emp set dept=#{dept},job=#{job} where eid=#{eid};
    </update>
    <delete id="delEmp" parameterType="int">
        delete from emp where eid=#{eid};
    </delete>
    <select id="dongtai" resultType="com.wang.bean.Emp">
        select*from emp where ename=#{ename} and dept=#{dept} and job=#{job};
    </select>
</mapper>

7.在com.wang.test包中创建测试类EmpTest在里面编写测试的方法

package com.wang.test;

import com.wang.bean.Emp;
import com.wang.dao.EmpDao;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class EmpTest {
    InputStream stream=null;
    SqlSessionFactoryBuilder builder=null;
    SqlSessionFactory factory=null;
    SqlSession sqlSession=null;
    EmpDao empDao=null;
    @Before
    public void init() throws IOException {
        stream= Resources.getResourceAsStream("mybatis.xml");
        builder=new SqlSessionFactoryBuilder();
        factory=builder.build(stream);
        sqlSession=factory.openSession();
        empDao=sqlSession.getMapper(EmpDao.class);
    }
    @Test
    public void testSelect(){
        List<Emp> empList = empDao.selectAll();
        for (Emp emp:empList){
            System.out.println(emp);
        }
    }
    @Test
    public void testselectByid(){
        Emp emp = empDao.selectById(3);
        System.out.println(emp);
    }
    @Test
    public void testAdd(){
        Emp emp=new Emp();
        emp.setEname("张三");
        emp.setDept("测试部");
        emp.setJob("测试工程师");
        emp.setSal(8800);
        emp.setPhone("15979898956");
        emp.setAddress("焦作");
        int n = empDao.addEmp(emp);
        if (n>0){
            System.out.println("成功");
        }else{
            System.out.println("失败");
        }
    }
    @Test
    public void testUpdate(){
        Emp old = empDao.selectById(3);
        System.out.println("修改前:"+old);
        old.setDept("运维部");
        old.setJob("运维工程师");
        empDao.reviseEmp(old);
        Emp emp1=empDao.selectById(3);
        System.out.println("修改后:"+emp1);
    }
    @Test
    public void testDel(){
        int n = empDao.delEmp(9);
        if (n>0){
            System.out.println("成功");
        }else{
            System.out.println("失败");
        }
    }
    @Test
    public void testDongtai(){
        Emp emp = empDao.dongtai("刘瑞琳", "运维部", "产品经理");
        System.out.println(emp);
    }
    @After
    public void destory() throws IOException {
        sqlSession.commit();
        sqlSession.close();
        stream.close();
    }
}