Mybatis对数据库数据举行增删改查 - IT评测·应用市场-qidao123.com

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>Mybatis</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.10</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.26</version>
</dependency>
</dependencies>
</project>

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<?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="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis_demo?useSSL=false&serverTimezone=UTC"/>
<property name="username" value="root"/>
<property name="password" value="your_password"/>
</dataSource>
</environment>
</environments>
<mappers>
<package>com.example.mybatis.mapper</package>
</mappers>
</configuration>

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package com.example.mybatis;
public class User {
private Integer id;
private String username;
private String addr;
private Integer age;
// 生成对应的getter和setter方法
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getAddr() {
return addr;
}
public void setAddr(String addr) {
this.addr = addr;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", addr='" + addr + '\'' +
", age=" + age +
'}';
}
}

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package com.example.mybatis.mapper;
import com.example.mybatis.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import java.util.List;
public interface UserMapper {
// 查询所有用户
@Select("SELECT * FROM user")
List<User> findAllUsers();
// 根据id查询用户
@Select("SELECT * FROM user WHERE id = #{id}")
User findUserById(Integer id);
// 新增用户
@Insert("INSERT INTO user (username, addr, age) VALUES (#{username}, #{addr}, #{age})")
int insertUser(User user);
// 更新用户信息
@Update("UPDATE user SET username = #{username}, addr = #{addr}, age = #{age} WHERE id = #{id}")
int updateUser(User user);
// 删除用户
@Delete("DELETE FROM user WHERE id = #{id}")
int deleteUser(Integer id);
}

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<?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.example.mybatis.mapper.UserMapper">
<select id="findAllUsers" resultMap="UserResultMap">
SELECT * FROM user
</select>
<resultMap id="UserResultMap" type="com.example.mybatis.User">
<id property="id" column="id"/>
<result property="username" column="username"/>
<result property="addr" column="addr"/>
<result property="age" column="age"/>
</resultMap>
</mapper>

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<mappers>
<mapper resource="com/example/mybatis/mapper/UserMapper.xml"/>
</mappers>

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package com.example.mybatis;
import com.example.mybatis.mapper.UserMapper;
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.jupiter.api.Test;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
import static org.junit.jupiter.api.Assertions.*;
public class MybatisTest {
@Test
public void testFindAllUsers() throws IOException {
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
List<User> userList = userMapper.findAllUsers();
assertNotNull(userList);
for (User user : userList) {
System.out.println(user);
}
sqlSession.close();
}
@Test
public void testFindUserById() throws IOException {
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.findUserById(1);
assertNotNull(user);
System.out.println(user);
sqlSession.close();
}
@Test
public void testInsertUser() throws IOException {
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User newUser = new User();
newUser.setUsername("赵六");
newUser.setAddr("深圳");
newUser.setAge(26);
int result = userMapper.insertUser(newUser);
sqlSession.commit();
assertEquals(1, result);
sqlSession.close();
}
@Test
public void testUpdateUser() throws IOException {
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User updateUser = userMapper.findUserById(1);
updateUser.setUsername("张三改");
updateUser.setAddr("北京改");
updateUser.setAge(26);
int result = userMapper.updateUser(updateUser);
sqlSession.commit();
assertEquals(1, result);
sqlSession.close();
}
@Test
public void testDeleteUser() throws IOException {
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
int result = userMapper.deleteUser(3);
sqlSession.commit();
assertEquals(1, result);
sqlSession.close();
}
}

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