Mybatis

1:pom.xml中导入坐标

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.25</version>
</dependency>
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.3.0</version>
</dependency>
<dependency>

配置jdbc.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/jdbc1?characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghai&rewriteBatchedStatements=true
jdbc.username=root
jdbc.password=010429

2：创建sqlMapConfig.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>
<!--  通过properties标签加载外部文件-->
    <properties resource="jdbc.properties"></properties>

    <environments default="development">
        <!--配置mysql的环境，注意，default中的属性，与下边environment中id的属性是一样的-->
        <environment id="development">
            <!--配置事务的类型-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置数据源，也叫作连接池-->
            <dataSource type="POOLED">
                <!--配置连接数据库的四个基本信息-->
                <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>

    <!--指定映射配置文件的位置，映射配置文件指的是每个dao独立的配置文件-->
    <mappers>
        <!--指定文件的位置，要与main中java的文件结构位置相同-->
        <mapper resource="com/xiaoze/mapper/UsersMapper.xml"></mapper>
    </mappers>

</configuration>

3：创建UsersMapper.xml映射文件

<?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="UsersMapper">
<!--    查询操作-->
    <select id="findAll" resultType="com.xiaoze.domain.Users" >
        select * from users
    </select>
<!--    插入操作-->
    <insert id="save" parameterType="com.xiaoze.domain.Users">
        insert into users values(#{id},#{name},#{password},#{email},#{birthday})
    </insert>
<!--    修改操作-->
    <update id="update" parameterType="com.xiaoze.domain.Users">
        update  users set  password=#{password} where id = #{id}
    </update>
<!--    删除操作-->
    <delete id="delete" parameterType="java.lang.Integer">
        delete from users where id = #{id}
    </delete>
</mapper>

4查询所有

//获取核心配置文件
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
//获取session工厂对象
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
//获取session会话对象
SqlSession sqlSession = build.openSession();
//执行操作，参数，namespace+id
List<Users> usersList = sqlSession.selectList("UsersMapper.findAll");
//打印数据
System.out.println(usersList);
//释放资源
sqlSession.close();

5修改

//2:插入操作
//模拟Users对象
Users users = new Users();
users.setId(7);
users.setPassword("55555");
//获取核心配置文件
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
//获取session工厂对象
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
//获取session会话对象
SqlSession sqlSession = build.openSession();
sqlSession.insert("UsersMapper.update",users);
//提交事务
sqlSession.commit();
//释放资源
sqlSession.close();

6：添加

//2:插入操作
//模拟Users对象
Users users = new Users();
users.setName("tom");
users.setPassword("6666222");
users.setEmail("Tom@qq.com");
users.setBirthday("1907-7-9");
//获取核心配置文件
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
//获取session工厂对象
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
//获取session会话对象
SqlSession sqlSession = build.openSession();
sqlSession.insert("UsersMapper.save",users);
//提交事务
sqlSession.commit();
//释放资源
sqlSession.close();

7：删除

//获取核心配置文件
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
//获取session工厂对象
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
//获取session会话对象
SqlSession sqlSession = build.openSession();
sqlSession.delete("UsersMapper.delete",7);
//提交事务
sqlSession.commit();
//释放资源
sqlSession.close();