MyBatis增删改——idea

1、创建maven工程，并创建对应包，类，接口，配置文件

2、pom.xml导入jar包依赖



mysql
mysql-connector-java
8.0.11


org.mybatis
mybatis
3.5.2


junit
junit
4.12





src/main/resources

**/*.properties
**/*.xml

false


src/main/java

**/*.properties
**/*.xml

false





3、配置mybatis-config配置文件


PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">



4、配置db.properties文件

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/数据库?useSSL=false&allowPublicKeyRetrieval=true&serverTimezOne=UTC
username=数据库用户名
password=数据库密码


5、编写工具类MyBatisUntil

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 java.io.IOException;
import java.io.InputStream;
//工具类
public class MyBatisUntil {
private static SqlSessionFactory sqlSessionFactory;
static {
try {
//获取sqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessiOnFactory= new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException ioException) {
ioException.printStackTrace();
}
}
//创建sqlSession对象
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}


6、创建数据库表，以及对应实体类

create table user(

id integer auto_increment PREPARE key,

name varchar(20),

pwd varchar(20)

);

public class User {
private int id;
private String name;
private String pwd;
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + ''' +
", pwd='" + pwd + ''' +
'}';
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public User() {
}
public User(int id, String name, String pwd) {
this.id = id;
this.name = name;
this.pwd = pwd;
}


7、创建接口

package dao;
import pojo.User;
import java.util.List;
import java.util.Map;
public interface UserMapper {
//获取全部用户
List getUserList();
//根据id查询用户
User getUserById(int id);
//添加用户
public int AddUser(User user);
//修改用户
int updateUser(User user);
//删除用户
int deleteUser(int id);
}


8、创建对应接口UserMapper.xml配置文件


PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">


select * from user



select * from user where id = #{id}


insert into user (id,name ,pwd) values (#{id},#{name},#{pwd})


update user set name=#{name },pwd=#{pwd} where id=#{id}


delete from user where id=#{id}




9、到mybatis-config配置文件中注册UserMapper

10、创建测试类

package dao;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import pojo.User;
import until.MyBatisUntil;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class UserDaoTest {
@Test
public void test1(){
//获取sqlSession对象
SqlSession sqlSession = MyBatisUntil.getSqlSession();
//执行
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//循环打印查找数据
List userList = mapper.getUserList();
for (User user : userList) {
System.out.println(user);
}
//关闭
sqlSession.close();
}
@Test
public void test2(){
SqlSession sqlSession = MyBatisUntil.getSqlSession();
//获取类mapper接口
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
System.out.println(mapper.getUserById(1));
sqlSession.close();
}
//增删改要提交事务
@Test
public void test3(){
SqlSession sqlSession = MyBatisUntil.getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
int res = mapper.AddUser(new User(4, "小小", "12345"));
//提交事务,不能漏掉
sqlSession.commit();
sqlSession.close();
}
@Test
public void test4(){
SqlSession sqlSession = MyBatisUntil.getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
mapper.updateUser(new User(4,"小睡","2323"));
sqlSession.commit();
sqlSession.close();
}
@Test
public void test5(){
SqlSession sqlSession = MyBatisUntil.getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
mapper.deleteUser(4);
sqlSession.commit();
sqlSession.close();
}
}


完工