在mapper中
namespace给文件重新命名
在select中
需要完整的select sql语句
在mybatis中需要
selcet id
select语句中占位符不在使用?而使用sql
parameterType中放置类型
************根据ID查询************
1> HelloMybatis.java
public class HelloMyBatis{
@Test
public void Test()ThrowsIOException{
//配置文件路径
String resource = "sqlMapConfig.xml";
//读取配置文件
InputStream in = Resource.getResourceAsStream(resource);
//需要sqlSessionFactoryBuilder
SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
//创建sqlSessionFactory
SqlSessionFactory ssf = ssfb.build(in);
//创建sqlSession
SqlSession session = ssf.openSession();
//操作数据库
//参数1:要操作的sql语句 参数2:sql语句的参数
User user = session.selectOne("UserMapper.selectUserById",1);
System.out.println(user);
}
}
2> UserMapper.xml
<mapper namespace="UserMapper">
<select id="selectUserById" parameterType="Integer" resultType="com.XXX.bean.User">
select * from user where u_id = #{id}
</select>
</mapper>
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3>引入日志文件log4j.properties
#日志级别
log4j.rootLogger = DEBUG,stdout
#控制台输出
log4j.appender.stdout=org.apache.log4j.ConsoleApperder
log4j.appender.stdout.layout=org.apache.log4j.Patternlayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
注:笔记内容只是记录,未进行实测