[Articles] MyBatis two .mybatis CRUD

mybaits CRUD

github源码(day52-mybatis-crud)：https://github.com/1196557363/ideaMavenProject.git

Dependence to guide pom.xml

	<!-- junit依赖 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!-- mybatis依赖 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.5</version>
    </dependency>

    <!-- MySQL数据库依赖 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.6</version>
    </dependency>

2. Create a configuration file mybatis-config.xml and create a table user_crud

<?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>
    <!--环境-->
    <environments default="dev_mysql">
        <environment id="dev_mysql">
            <!--事务管理器-->
            <transactionManager type="JDBC"></transactionManager>
            <!--mybatis提供的连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis1" />
                <property name="username" value="root" />
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>
    <!-- 映射接口 -->
    <mappers>
        <mapper resource="wpj/mapper/IUserDao.xml" />
    </mappers>
</configuration>

3. Define bean

package wpj.bean;

/**
 * ClassName: User
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2019\12\31 0031 11:20
 * @since JDK 1.8
 */
public class User {
    private String name;
    private int age;
    public User() { }
    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public int getAge() { return age; }
    public void setAge(int age) { this.age = age; }
    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

4. The definition of the interface

package wpj.dao;

import wpj.bean.*;
import java.util.*;

/**
 * ClassName: IUserDao
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2019\12\31 0031 11:22
 * @since JDK 1.8
 */
public interface IUserDao {
    // 查询所有
    List<User> selectAllUser();
    
    // 根据id查找User   id为主键 只存在一个
    User selectUserById(int id);
    
    // 根据name查找User(age同理) name可重复 可能查出多个
    List<User> selectUsersByName(String name);

    // 根据Id修改User
    int updateUserById(User user);

    // 根据ID删除User
    int deleteUserById(int id);
    
    // 添加User
    int insertUser(User user);

}

5. Write the corresponding interface XML IUserDao.xml

<?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="wpj.dao.IUserDao">
	<!-- 查询所有 id和dao接口的方法一致 下同 -->
    <select id="selectAllUser" resultType="wpj.bean.User">
        select * from user_crud
    </select>
    
	<!-- 根据id查询 -->
    <select id="selectUserById" resultType="wpj.bean.User">
        select * from user_crud where id = #{id}
    </select>

    <!-- 根据name查询 -->
    <select id="selectUsersByName" resultType="wpj.bean.User">
        select * from user_crud where name = #{name}
    </select>
    
	<!-- 根据id修改 -->
    <update id="updateUserById">
        update user_crud set name = #{name} where id = #{id}
    </update>
    
	 <!-- 根据id删除 -->
    <delete id="deleteUserById">
        delete from user_crud where id = #{id}
    </delete>
    
    <!-- 添加 -->
    <insert id="insertUser">
        insert into user_crud(id, name, age) values(#{id}, #{name}, #{age})
    </insert>

</mapper>

6. Test

package wpj;

import org.apache.ibatis.io.*;
import org.apache.ibatis.session.*;

import java.io.*;

/**
 * ClassName: TestCrud
 * Description:
 *
 * @author JieKaMi
 * @version 1.0
 * @date: 2019\12\31 0031 11:34
 * @since JDK 1.8
 */
public class TestCrud {
	// 抽取sqlSeesionFactory
    public static SqlSessionFactory getSqlSeesionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        return sqlSessionFactory;
    }
    
}

6.1 All inquiries

	/**
     * 查询所有
     * @throws IOException
     */
	@Test
    public void TestSelectAllUser() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        List<User> userList = sqlSession.selectList("wpj.dao.IUserDao.selectAllUser");
        for(User user : userList) {
            System.out.println(user);
        }
    }
    /**
     * 查询所有	第二种方式
     * @throws IOException
     */
    @Test
    public void TestSelectAllUser() throws IOException {
    
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        List<User> userList = mapper.selectAllUser();
        for(User user : userList) {
            System.out.println(user);
        }
    }

6.2 (primary key) lookup based on the ID

	/**
     * 根据ID查询
     * @throws IOException
     */
	@Test
    public void TestSelectUserById() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        User user = sqlSession.selectOne("wpj.dao.IUserDao.selectUserById",1);
        System.out.println(user);
    }
	/**
     * 根据ID查询	第二种方式
     * @throws IOException
     */
	@Test
    public void TestSelectUserById() throws IOException {
		SqlSession sqlSession = getSqlSeesionFactory().openSession();
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        User user = mapper.selectUserById(1);
        System.out.println(user);
    }

6.1 based on name (repeatable) Find

	/**
     * 根据Name查询
     * @throws IOException
     */
    @Test
    public void TestSelectUsersByName() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        List<User> userList = sqlSession.selectList("wpj.dao.IUserDao.selectUsersByName","jieKaMi");
        for(User user : userList) {
            System.out.println(user);
        }
    }
	/**
     * 根据Name查询	第二种方式
     * @throws IOException
     */
    @Test
    public void TestSelectUsersByName() throws IOException {

        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        List<User> userList = mapper.selectUsersByName("jieKaMi");
        for(User user : userList) {
            System.out.println(user);
        }

    }
	

6.1 According to revise ID

	/**
     * 根据id修改
     * @throws IOException
     */
	@Test
    public void TestUpdateUserById() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        User user = new User(1, "jieKaMi2333", 15);

        int result = sqlSession.update("wpj.dao.IUserDao.updateUserById",user);
        sqlSession.commit();
        System.out.println("修改: " + (result == 1));
    }
    
	/**
     * 根据id修改	第二种方式
     * @throws IOException
     */
    @Test
    public void TestUpdateUserById() throws IOException {

        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        User user = new User(1, "jieKaMi2333", 15);
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        int result = mapper.updateUserById(user);

        sqlSession.commit();

        System.out.println("修改: " + (result == 1));

    }

6.1 Delete according to ID

	/**
     * 根据id删除
     * @throws IOException
     */
	@Test
    public void TestDeleteUserById() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        int result = sqlSession.update("wpj.dao.IUserDao.deleteUserById",1);
        sqlSession.commit();
        System.out.println("删除: " + (result == 1));
    }

	/**
	 * 根据id删除 第二种方式
	 */
	@Test
    public void TestDeleteUserById() throws IOException {
		SqlSession sqlSession = getSqlSeesionFactory().openSession();
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        int result = mapper.deleteUserById(1);
        sqlSession.commit();
        System.out.println("修改: " + (result == 1));
	  }

6.1 insert Bean

	/**
     * 添加Bean
     * @throws IOException
     */
	@Test
    public void TestInsertUser() throws IOException {
        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        User user = new User(1,"jieKaMi",22);
        
        int result = sqlSession.update("wpj.dao.IUserDao.insertUser",user);
        sqlSession.commit();
        System.out.println("修改: " + (result == 1));
    }

	/**
     * 添加Bean 第二种方式
     * @throws IOException
     */
    @Test
    public void TestInsertUser() throws IOException {

        SqlSession sqlSession = getSqlSeesionFactory().openSession();
        IUserDao mapper = sqlSession.getMapper(IUserDao.class);
        User user = new User(1,"jieKaMi",22);
        int result = mapper.insertUser(user);
        sqlSession.commit();
        System.out.println("修改: " + (result == 1));

    }