mybatis基础

Posted 2021-03-18 fpflog

1、引入jar包

2、将 log4j.properties  copy到src --main --resources下

3、创建实体类

4、创建操作接口类

package com.fpf.dao;

import com.fpf.domain.User;

import java.util.List;

public interface UserDao {
    /*

    查询所用用户
     */
    public List<User> findAll();
    /*
    * 保存用户
    * */
    public void save(User user);
    /*
    * 更新用户
    * */
    public void update(User user);
    /*
    * 删除用户
    * */
    public void delete(int id);
    /*
    * 模糊查询
    * */
    public  List<User> selectLike(String uname);
}

5、在src --main --resources创建configuration.xml

其目的是配置数据库信息 ，引用mappers信息

<?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="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"></property>
                <property name="url" value="jdbc:mysql://localhost:3306/test"></property>
                <property name="username" value="root"></property>
                <property name="password" value="root"></property>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/fpf/Dao/UserDao.xml"></mapper>
    </mappers>
</configuration>
6、配置mapper
将mapper放在src --main --resources 自建文件夹将xxxmapper.xml配置好

<?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.fpf.dao.UserDao">
    <select id="findAll" resultType="com.fpf.domain.User">
      SELECT * from user;
    </select>
    <insert id="save" parameterType="com.fpf.domain.User">
        insert into user (username,password,name,sex,brithday) values(#{username},#{password},#{name},#{sex},#{brithday});
    </insert>
    <update id="update" parameterType="com.fpf.domain.User">
        update user set username=#{username} where id=#{id};
    </update>
    <delete id="delete" parameterType="int">
        delete from user where id=#{uid};
    </delete>
    <select id="selectLike" parameterType="String" resultType="com.fpf.domain.User">
        select * from user where name like #{name};
    </select>
</mapper>
注：

namespace对应所用类   id对应方法名称    parameterType对应出入数据类型 类型为自带类型#{任意定义} 类型为自定义类型类#{与实体类属性值对应}     resultType对应返回数据类型    
7、建立测试类

package com.fpf.test;

import com.fpf.dao.UserDao;
import com.fpf.domain.User;
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.After;
import org.junit.Before;
import org.junit.Test;



import java.io.InputStream;
import java.util.Date;
import java.util.List;

public class UserTest {
    InputStream in;
    SqlSessionFactoryBuilder builder;
    SqlSessionFactory factory;
    SqlSession session;
    UserDao mapper;
    @Before
    public void init()throws Exception{
        //获取xml
        in= Resources.getResourceAsStream("MySqlConfigration.xml");
        //构建创建者
       builder=new SqlSessionFactoryBuilder();
        //构建工厂
        factory= builder.build(in);
        //创建对象
         session = factory.openSession();
         mapper = session.getMapper(UserDao.class);
    }
    @After
    public void destroy() throws  Exception{
        session.commit();
        session.close();
        in.close();
    }
    @Test
    public void findAllTest() {
        List<User> all = mapper.findAll();
        for (User user : all) {
            System.out.println(user);
        }

    }
    @Test
    public void saveTest(){
        User user=new User();
        user.setUsername("zhangliang");
        user.setPassword("123456");
        user.setName("张良");
        user.setSex("男");
        user.setBrithday(new Date());
        mapper.save(user);
    }
    @Test
    public void updateTest(){
        User user=new User();
        user.setId(2);
        user.setUsername("zl");
        mapper.update(user);
    }
    @Test
    public void deleteTest(){
      mapper.delete(2);
    }
    @Test
    public void selectLikeTest(){
        List<User> users = mapper.selectLike("%小%");
        for (User user : users) {
            System.out.println(user);
        }

    }

}