mybatis入门demo

  1. 创建数据库
  2. mysql创建user表
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    CREATE TABLE `user`  (
  `id` int(32) NOT NULL COMMENT 'id\r\n',
  `name` varchar(60) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `sex` varchar(1) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `birthday` date NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;
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  3. 创建maven普通工程mybatis-parent，删除src目录，添加mybatis依赖。

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    <!--添加mybatis依赖-->
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.3</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
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  4. 创建子模块mybatis-01
  5. resources目录下创建配置文件mybatis-config.xml
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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.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/qiaob/mapper/UserMapper.xml"/>
    </mappers>
</configuration>
    View Code
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  6. 封装mybatis工具类
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    package com.qiaob.utils;

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.Test;

import java.io.IOException;
import java.io.InputStream;

public class MybatisUtils {
    static {
        //使用mybatis第一步：获取sqlSessionFactory对象
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = null;
            inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private static SqlSessionFactory sqlSessionFactory;

    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }


}
    View Code
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  7. 生成pojo实体类
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    package com.qiaob.pojo;

import java.util.Date;

public class User {
    private int id;
    private String name;
    private String sex;
    private Date birthday;

    public User() {
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", birthday=" + birthday +
                '}';
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
}
    View Code
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  8. 生成mapper数据层接口
    复制代码
    package com.qiaob.mapper;

    import com.qiaob.pojo.User;

    import java.util.ArrayList;

    public interface UserMapper {
        //查询所有
        public ArrayList<User> getUserList();

        //根据id查询某个
        public User getUserById(int id);


        //插入用户
        public int addUser(User user);

        //更新用户
        public int updateUser(User user);

        //删除用户
        public int deleteUser(int id);

    }
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8.　　在resources相同层级目录下创建UserMapper.xml

<mapper namespace="com.qiaob.mapper.UserMapper">:代表实现哪个mapper的接口方法
id="getUserList" :对应mapper的方法名

resultType="com.qiaob.pojo.User":对应返回集类型
parameterType="com.qiaob.pojo.User":sql中可以直接调用属性
sqlSession.commit()：mybatis要手工提交事务才生效
 
复制代码
<?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.qiaob.mapper.UserMapper">
    <select id="getUserList" resultType="com.qiaob.pojo.User">
    select * from mybatis.user
  </select>

    <select id="getUserById" resultType="com.qiaob.pojo.User" parameterType="int">
        select * from mybatis.user where id = #{id}
    </select>

    <insert id="addUser" parameterType="com.qiaob.pojo.User">
      insert into mybatis.user(id, name, sex, birthday) values (#{id},#{name},#{sex},#{birthday})
    </insert>
    <update id="updateUser" parameterType="com.qiaob.pojo.User">
        update mybatis.user set birthday = #{birthday}  where  id=#{id};
    </update>
    <delete id="deleteUser" parameterType="int">
        delete from mybatis.user where id =#{id}
    </delete>
</mapper>
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9.创建单元测试类
  • 获得指定日期的方法
?
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SimpleDateFormat sdf =  new SimpleDateFormat( "yyyy-MM-dd" );
       Date d = null ;
       try {
            d = sdf.parse( "2018-03-09" );
       }  catch (ParseException e) {
           e.printStackTrace();
       }

　　

 
复制代码
package com.qiaob.dao;

import com.qiaob.mapper.UserMapper;
import com.qiaob.pojo.User;
import com.qiaob.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class UserDaoTest {
    @Test
    public void testUserList(){
        //第一步：获得sqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //第二步：执行sql
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        ArrayList<User> userList = mapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }

        //第三步：关闭sqlSession
        sqlSession.close();
    }


    @Test
    public  void testGetUserById(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = mapper.getUserById(1);
        System.out.println(user);

        sqlSession.close();
    }

    @Test
    public  void testSaveUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        User user = new User(3, "乔逸之", "1", new Date());
        int num = mapper.addUser(user);

        System.out.println(num);

        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void testUpdate(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date d =null;
        try {
             d = sdf.parse("2018-03-09");
        } catch (ParseException e) {
            e.printStackTrace();
        }

        mapper.updateUser(new User(3,"乔逸之","1",d));

        sqlSession.commit();
        sqlSession.close();
    }


    @Test
    public void testDeleteUser( ){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.deleteUser(3);
        sqlSession.commit();
        sqlSession.close();
    }

}
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 补充：如果想将mapper.xml和mapper放在同一路径下，则需要在pom文件中增加导出过滤，见博客《关于在maven项目中配置文件资源导出问题》。

 
posted @   qiaoyizhi  阅读(77)  评论(0)  编辑  收藏  举报
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