【Mybatis】XML配置实现增删改查

①创建数据库和表，数据库为mytest，表为users

 1 CREATE DATABASE mytest;
 2 USE mytest;
 3 
 4 
 5 DROP TABLE IF EXISTS users;
 6 CREATE TABLE users(
 7 id INT PRIMARY KEY auto_increment NOT NULL,
 8 name VARCHAR(20),
 9 age INT
10 )

②创建Java工程，导入相应的jar包

③创建配置文件conf.xml和数据库配置文件db.properties

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 
 3     "http://mybatis.org/dtd/mybatis-3-config.dtd">
 4     
 5 <configuration>
 6 
 7     <properties resource="db.properties"></properties>
 8     <environments default="development">
 9         <environment id="development">
10             <transactionManager type="JDBC"></transactionManager>
11             <dataSource type="POOLED">
12                 <property name="driver" value="${driver}"/>
13                 <property name="url" value="${url}"/>
14                 <property name="username" value="${name}"/>
15                 <property name="password" value="${password}"/>
16             </dataSource>
17         </environment>
18     </environments>
19 </configuration>

conf.xml

1 driver = com.mysql.jdbc.Driver
2 url = jdbc:mysql://localhost:3306/mytest
3 name = root
4 password = root

④创建实体类User

 1 package org.mybatis.domain;
 2 
 3 public class User {
 4 
 5     private int id;
 6     private String name;
 7     private int age;
 8     
 9     public int getId() {
10         return id;
11     }
12     public void setId(int id) {
13         this.id = id;
14     }
15     public String getName() {
16         return name;
17     }
18     public void setName(String name) {
19         this.name = name;
20     }
21     public int getAge() {
22         return age;
23     }
24     public void setAge(int age) {
25         this.age = age;
26     }
27     @Override
28     public String toString() {
29          return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
30     }
31     
32 }

⑤创建sql映射文件userMapper.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
 3     "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 4     
 5 <mapper namespace="org.mybatis.mapping.userMapper">
 6     <!-- 根据id查询得到一个user对象 -->
 7     <select id="getUser" parameterType="int" resultType="org.mybatis.domain.User">
 8         select * from users where id=#{id}
 9     </select>
10     
11     <select id="getAllUsers" resultType="org.mybatis.domain.User">
12         select * from users
13     </select>
14     
15     <insert id="addUser" parameterType="org.mybatis.domain.User">
16         insert into users(name, age) values (#{name}, #{age})
17     </insert>
18     
19     <update id="updateUser" parameterType="org.mybatis.domain.User">
20         update users set name=#{name}, age=#{age} where id=#{id}
21     </update>
22     
23     <delete id="deleteUser" parameterType="int">
24         delete from users where id=#{id}
25     </delete>
26 </mapper>

userMapper.xml

⑥向配置文件中注册 userMapper.xml 文件

1 <mappers>
2         <mapper resource="org/mybatis/mapping/userMapper.xml"/>
3     </mappers>
4 
5 
6 </configuration>

conf.xml

⑦测试类

 1 package org.mybatis.app;
 2 
 3 import java.io.InputStream;
 4 import java.util.List;
 5 
 6 import org.apache.ibatis.session.SqlSession;
 7 import org.apache.ibatis.session.SqlSessionFactory;
 8 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 9 import org.junit.Before;
10 import org.junit.Test;
11 import org.mybatis.domain.User;
12 
13 public class TestXML {
14 
15     SqlSession session;
16     
17     @Before
18     public void beforeLoadXML(){
19         //加载 mybatis 配置文件
20         InputStream inputStream = TestXML.class.
21                 getClassLoader().getResourceAsStream("conf.xml");
22         //构建sqlSession的工厂
23         SqlSessionFactory sqlSessionFactory =
24                 new SqlSessionFactoryBuilder().build(inputStream);
25         //根据 sqlSessionFactory 产生 session
26         session = sqlSessionFactory.openSession();
27     }
28     
29     //插入数据
30     @Test
31     public void addOneUser() {
32         String statement = "org.mybatis.mapping.userMapper.addUser";
33         User user = new User();
34         user.setName("666");
35         user.setAge(66);
36         session.insert(statement, user);
37         session.commit();
38         session.close();
39     }
40     
41     
42     //根据id查询user表中的数据
43     @Test
44     public void getOneUser(){
45         String statement = "org.mybatis.mapping.userMapper.getUser";
46         User user = session.selectOne(statement, 1);
47         System.out.println(user);
48         session.close();
49     }
50     
51     //查询所有数据
52     @Test
53     public void getAllUser() {
54         String statement = "org.mybatis.mapping.userMapper.getAllUsers";
55         List<User> listUser = session.selectList(statement);
56         System.out.println(listUser);
57         session.close();
58     }
59     
60     //更新数据
61     //session.update(statement, user);
62     //删除数据
63     //session.delete(statement, 1);
64 }

⑧结构图为：