MyBitis(iBitis)系列随笔之三：简单实现CRUD

MyBitis(iBitis)系列随笔之一：MyBitis入门实例

MyBitis(iBitis)系列随笔之二：类型别名(typeAliases)与表-对象映射(ORM)

MyBitis(iBitis)系列随笔之三：简单实现CRUD

MyBitis(iBitis)系列随笔之四：多表(多对一查询操作)

MyBitis(iBitis)系列随笔之五：多表(一对多关联查询)

MyBitis(iBitis)系列随笔之六：mybitis与spring集成

Mybitis(iBitis)实现对对象增删改查操作要借助<select/>查询，<insert/>增加，<update/>更新，<delete/>删除 标签来操作。

值得注意的有两点：

1、在对对象进行增删改时，SqlSession session = sqlSessionFactory.openSession();获取的session。必选执行session.commit();否则操作无效。

2、Mybitis与hibernate一样，插入数据后会把id值赋值给缓存中对象

还是接着上一讲的代码继续改动

UserMapper.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">
<mapper namespace="user">
<resultMap id="userResultMap" type="user">
<id property="id" column="id"/>
<result property="userName" column="name"/>
<result property="password" column="pass"/>
</resultMap>

<!--resultType 表示com.jefry.User这样一个实体对象 -->
<select id="selectUser" parameterType="int"  resultMap="userResultMap" >
select * from t_user where id = #{id}
</select>

<!--增加操作-->
<insert id="addUser" parameterType="user"
useGeneratedKeys="true" keyProperty="id">
insert into t_user(name,pass) values(#{userName},#{password})
</insert>

<!--更新操作-->
<update id="modifyUser" parameterType="user">
update t_user set name=#{userName}, pass=#{password} where id=#{id}
</update>

<delete id="deleteUser" parameterType="int">
delete from t_user where id=#{id}
</delete>

</mapper>

测试代码

public class Test {
static String resource = "mybatis-config.xml";

public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession session = sqlSessionFactory.openSession();
try {
//User.selectUser中User对应UserMapper.xml文件中标签<mapper namespace="User"> namespace的值
//selectUser 对应UserMapper.xml文件中标签<select id="selectUser" parameterType="int" resultType="com.jefry.User">中id值
User user = session.selectOne("user.selectUser", 1);
System.out.println("user.getName()=" +  user.getPassword());

User addUser = new User();
addUser.setUserName("NEWWWWW");
addUser.setPassword("111111");
session.insert("user.addUser", addUser);

//插入操作
User modifyUser = new User();
modifyUser.setUserName("NEWWWWW");
modifyUser.setPassword("111111");
modifyUser.setId(1);

//修改用户
session.update("user.modifyUser", addUser);

//删除操作
session.delete("user.deleteUser",2);

//这里必须commit,否则增删改无效
session.commit();

//与hibernate一样，插入数据后会把id值赋值给缓存中的id
System.out.println("addUser.getId()" + addUser.getId() );

} finally {
session.close();
}
}

}