Mybatis学习三（CRUD）

1.示例

第一步：配置数据源和对象（表）的映射

加入所需的 jar 包：mysql-connector 和 mybatis3.jar。配置 src/config/Configure.xml

<?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>
<typeAliases>
<typeAlias alias="User" type="com.yiibai.mybatis.models.User" />
</typeAliases>

第二步：配置表对象（实体类）

public class User {
private int id;
private String name;
private String dept;
private String phone;
private String website;
}

第三步：配置接口

import java.util.List;

import org.apache.ibatis.annotations.Select;
import com.yiibai.mybatis.models.User;

   public interface IUser {
   //@Select("select * from user where id= #{id}")
   //public User getUserByID(int id);
   public List<User> getUserList();

public void insertUser(User user);

public void updateUser(User user);

public void deleteUser(int userId);

public User getUser(int id);
}

第四步：配置映射文件（User.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">

<select id="getUser" parameterType="int"
   resultType="com.yiibai.mybatis.models.User">
SELECT *
   FROM USER
WHERE id = #{userId}
   </select>

<insert id="insertUser" parameterType="User">
INSERT INTO USER(name,
dept, website,phone)
VALUES(#{name}, #{dept}, #{website}, #{phone})
</insert>

   <select id="getUserList" resultType="com.yiibai.mybatis.models.User">
   SELECT * FROM USER
   </select>

<update id="updateUser" parameterType="User">
   UPDATE USER
SET
   name=
#{name},
         dept = #{dept},
   website = #{website},
phone = #{phone}
         WHERE
         id =
         #{id}
</update>

<delete id="deleteUser" parameterType="int">
DELETE FROM USER WHERE id = #{id}
</delete>

</mapper>

第五步：测试

import java.io.Reader;

import java.text.MessageFormat;
import java.util.List;
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 com.yiibai.mybatis.dao.IUser;
import com.yiibai.mybatis.models.User;

public class Main {
private static SqlSessionFactory sqlSessionFactory;
private static Reader reader;

   static {
   try {
   reader = Resources.getResourceAsReader("config/Configure.xml");
   sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (Exception e) {
   e.printStackTrace();
}
   }

public static SqlSessionFactory getSession() {
return sqlSessionFactory;
}

/**
* @param args
   */
public static void main(String[] args) {
// TODO Auto-generated method stub
   SqlSession session = sqlSessionFactory.openSession();
try {
   //sqlSessionFactory.getConfiguration().addMapper(IUser.class);
   //User user = (User) session.selectOne( "com.yiibai.mybatis.models.UserMapper.getUserByID", 1);

// 用户数据列表
getUserList();
// 插入数据
// testInsert();

// 更新用户
//testUpdate();

// 删除数据
//testDelete();

   } finally {
session.close();
   }
   }

   //
   public static void testInsert()
   {
try
   {
   // 获取Session连接
SqlSession session = sqlSessionFactory.openSession();
// 获取Mapper
IUser userMapper = session.getMapper(IUser.class);
             System.out.println("Test insert start...");
// 执行插入
User user = new User();
user.setId(0);
user.setName("Google");
             user.setDept("Tech");
             user.setWebsite("http://www.google.com");
             user.setPhone("120");
             userMapper.insertUser(user);
// 提交事务
session.commit();

// 显示插入之后User信息
             System.out.println("After insert");
             getUserList();
             System.out.println("Test insert finished...");
         }
         catch (Exception e)
         {
             e.printStackTrace();
         }
}

// 获取用户列表
public static void getUserList() {
         try {
             SqlSession session = sqlSessionFactory.openSession();
             IUser iuser = session.getMapper(IUser.class);
             // 显示User信息
             System.out.println("Test Get start...");
             printUsers(iuser.getUserList());
             System.out.println("Test Get finished...");
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static void testUpdate()
     {
         try
         {
             SqlSession session = sqlSessionFactory.openSession();
             IUser iuser = session.getMapper(IUser.class);
             System.out.println("Test update start...");
             printUsers(iuser.getUserList());
             // 执行更新
             User user = iuser.getUser(1);
             user.setName("New name");
             iuser.updateUser(user);
             // 提交事务
             session.commit();
             // 显示更新之后User信息
             System.out.println("After update");
             printUsers(iuser.getUserList());
             System.out.println("Test update finished...");
         }catch (Exception e)
         {
             e.printStackTrace();
         }
     }

     // 删除用户信息
     public static void testDelete()
     {
         try
         {
             SqlSession session = sqlSessionFactory.openSession();
             IUser iuser = session.getMapper(IUser.class);
             System.out.println("Test delete start...");
             // 显示删除之前User信息
             System.out.println("Before delete");
             printUsers(iuser.getUserList());
             // 执行删除
             iuser.deleteUser(2);
             // 提交事务
             session.commit();
             // 显示删除之后User信息
             System.out.println("After delete");
             printUsers(iuser.getUserList());
             System.out.println("Test delete finished...");
         }catch (Exception e)
         {
             e.printStackTrace();
         }
     }

     /**
      *
      * 打印用户信息到控制台
      *
      * @param users
      */
     private static void printUsers(final List<User> users) {
         int count = 0;

         for (User user : users) {
             System.out.println(MessageFormat.format(
                     "============= User[{0}]=================", ++count));
             System.out.println("User Id: " + user.getId());
             System.out.println("User Name: " + user.getName());
             System.out.println("User Dept: " + user.getDept());
             System.out.println("User Website: " + user.getWebsite());
         }
     }
}

学习来源：https://www.yiibai.com/mybatis/mybatis-curd.html#article-start

posted @ 2020-09-11 13:51 小窝蜗阅读(140) 评论(0) 编辑收藏举报

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Mybatis学习三 （CRUD）

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Mybatis学习三（CRUD）