IDEA+mybatis实现增删改查(CURD)
原文链接：这里
0.前言
操作mybaits和mysql进行增删改查是必备的一步，今天写一篇文章简单记录一下mybatis的增删改查操作。
1.具体操作
studnetsMapper文件
package com.cat.dao;
import com.cat.pojo.Students;
import java.util.List;
public interface StudentsMapper {
//所有学生
List<Students> listAllStudents();
//删除一名学生信息
int deleteStudent(int id);
//新增一名学生
int addStudent(Students students);
//修改一名学生信息
int updateStudentById(Students students);
}
StudentsMapper.xml文件
<?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.cat.dao.StudentsMapper">
<!--展示所有学生-->
<select id="listAllStudents" resultType="com.cat.pojo.Students">
select * from students;
</select>
<!--删除一条学生信息-->
<delete id="deleteStudent" parameterType="int">
delete from students where id = #{id}
</delete>
<!--增加一名学生信息-->
<insert id="addStudent" parameterType="com.cat.pojo.Students">
insert into students(stu_name,stu_sex,class_id,age)
values (#{stu_name},#{stu_sex},#{class_id},#{age})
</insert>
<!--更新一名学生的信息-->
<update id="updateStudentById" parameterType="com.cat.pojo.Students">
update students set
stu_name= #{stu_name},
stu_sex= #{stu_sex},
class_id =#{class_id},
age=#{age}
where id =#{id}
</update>
</mapper>
Test文件
package com.cat.test;
import com.cat.dao.StudentsMapper;
import com.cat.pojo.Students;
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.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MyBatisTest {
//输出所有学生信息
@Test
public void test() throws IOException{
//获得核心配置文件
InputStream in = Resources.getResourceAsStream("MyBatisConfig.xml");
//获得session工厂对象
SqlSessionFactoryBuilder builder =new SqlSessionFactoryBuilder();
SqlSessionFactory factory=builder.build(in);
SqlSession session =factory.openSession();
//获得会话对象
List<Students> students =session.selectList("listAllStudents");
System.out.println(students);
session.close(); //关闭
}
//测试删除一名学生信息
@Test
public void deleteStudent() throws IOException{
//获得核心配置文件
InputStream in = Resources.getResourceAsStream("MyBatisConfig.xml");
//获得session工厂对象
SqlSessionFactoryBuilder builder =new SqlSessionFactoryBuilder();
SqlSessionFactory factory=builder.build(in);
SqlSession session =factory.openSession();
//获得会话对象
StudentsMapper studentsMapper = session.getMapper(StudentsMapper.class);
studentsMapper.deleteStudent(1000); //调用deleteStudent方法，删除id是1000的这个学生
session.close(); //关闭
}
//新增一名学生信息
@Test
public void addStudent() throws IOException{
//获得核心配置文件
InputStream in = Resources.getResourceAsStream("MyBatisConfig.xml");
//获得session工厂对象
SqlSessionFactoryBuilder builder =new SqlSessionFactoryBuilder();
SqlSessionFactory factory=builder.build(in);
SqlSession session =factory.openSession();
//获得会话对象
StudentsMapper studentsMapper = session.getMapper(StudentsMapper.class);
//构造一个新的学生
Students s =new Students();
s.setStu_name("呵呵");
s.setClass_id(1042);
s.setAge(16);
s.setStu_sex("男");
int res = studentsMapper.addStudent(s); //调用
session.commit(); //增删改必须提交事务
session.close(); //关闭
}
//修改一名学生信息
@Test
public void updateStudent() throws IOException{
//获得核心配置文件
InputStream in = Resources.getResourceAsStream("MyBatisConfig.xml");
//获得session工厂对象
SqlSessionFactoryBuilder builder =new SqlSessionFactoryBuilder();
SqlSessionFactory factory=builder.build(in);
SqlSession session =factory.openSession();
//获得会话对象
StudentsMapper studentsMapper = session.getMapper(StudentsMapper.class);
//把原来的学生信息修改
Students s= new Students();
s.setId(1001); //定向修改id是1001的学生
s.setStu_name("李十三"); //这个人的名字改成李十三
s.setStu_sex("男"); //性别改为男
s.setAge(24); //年龄修改为24
s.setClass_id(3002);
int res = studentsMapper.updateStudentById(s); //调用
session.commit(); //增删改必须提交事务
session.close(); //关闭
}
}
