Mybatis入门增删改查学习笔记

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.32</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.5</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>

public class User {
    private int id;
    private String username;
    private String password;
    //省略set、get、tostring方法
}

<?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">

<!--namespace:命名空间，和下面id一起组成查询标识-->
<mapper namespace="userMapper">

    <!--查询所有-->
    <!--resultType：查询结果对应的实体类型-->
    <select id="findAll" resultType="user">
        select * from user
    </select>

    <!--插入操作-->
    <!--parameterType属性指定要插入的数据类型,#{实体属性名}方式引用实体中的属性值-->
    <insert id="save" parameterType="user">
        insert into user values(#{id},#{username},#{password});
    </insert>

    <!--修改操作-->
    <update id="update" parameterType="user">
        update user set username=#{username},password=#{password} where id = #{id};
    </update>

    <!--删除操作-->
    <delete id="delete" parameterType="int">
        delete from user where id = #{id};
    </delete>
</mapper>

<?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>

    <!--加载外部properties文件-->
    <properties resource="jdbc.properties"></properties>

    <!--配置typeAliases，为cn.guixinchn.domain.User定义别名为: user-->
    <typeAliases>
        <typeAlias type="cn.guixinchn.domain.User" alias="user"/>
    </typeAliases>

    <!--数据源环境-->
    <environments default="developement">
        <environment id="developement">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="{jdbc.driver}"/>
                <property name="url" value="{jdbc.url}"/>
                <property name="username" value="{jdbc.username}"/>
                <property name="password" value="{jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

    <!--加载映射文件-->
    <mappers>
        <mapper resource="cn/guixinchn/mapper/UserMapper.xml"></mapper>
    </mappers>
</configuration>

jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/test
jdbc.username = root
jdbc.password = 123456

@Test
public void test1() throws IOException {

    //模拟数据
    User user = new User();
    user.setUsername("测试");
    user.setPassword("123");


    // 获取核心配置文件
    InputStream resourceAsStream = Resources.getResourceAsStream("SqlMapConfig.xml");
    // 获取session工厂对象
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
    //获得session回话对象
    SqlSession sqlSession = sqlSessionFactory.openSession();
    //执行操作 参数: namespace+id

    //查询所有
    //List<User> userList = sqlSession.selectList("userMapper.findAll");
    //打印数据
    //System.out.println(userList);

    //插入操作
    //sqlSession.insert("userMapper.save",user);
    //提交数据
    //sqlSession.commit();

    //修改操作
    //sqlSession.update("userMapper.update",user);
    //sqlSession.commit();

    //删除操作
    //sqlSession.delete("userMapper.delete",4);
    //sqlSession.commit();

    //释放资源
    sqlSession.close();
}