mybatis

CURD


1.namespace

namespace中的包名要和Dao/mapper接口中的报名一致!

2.select

选择,查询语句

  • id:对应的namespace中的方法名
  • resultType:Sql语句执行的返回值!
  • parameterType:参数类型

3.Insert

<insert id="addUser" parameterType="com.zhang.pojo.User" >
    insert into jwxt.user(id, name, pwd)values(#{id},#{name},#{pwd});
</insert>

4.update

update jwxt.user set name=#{name},pwd=#{pwd} where id=#{id};

5.Delete

<delete id="deleteUser" parameterType="map">
    delete from jwxt.user where id=#{userid}
</delete>

Map

int updateUser2(Map<String,Object> map);
<update id="updateUser2" parameterType="map">
    update jwxt.user set pwd=#{pwd} where id=#{userid};
</update>
public void updateUser2() {
    SqlSession sqlSession = MybatisUtils.getsqlsession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    HashMap<String,Object>map=new HashMap<String, Object>();
    map.put("userid",4);
    map.put("pwd",98778963);
    mapper.updateUser2(map);
    sqlSession.commit();
    sqlSession.close();
}

生命周期

image-20210323190651156

ResultMap

<resultMap id="blogResult" type="Blog">
  <id property="id" column="blog_id" />
  <result property="title" column="blog_title"/>
  <collection property="posts" ofType="Post" resultMap="blogPostResult" columnPrefix="post_"/>
</resultMap>

<resultMap id="blogPostResult" type="Post">
  <id property="id" column="id"/>
  <result property="subject" column="subject"/>
  <result property="body" column="body"/>
</resultMap>

日志

Log4j

1.导入包import org.apache.log4j.Logger;

  • logger.info
  • logger.debug
  • logger.error

2.日志对象

logger.getlogger(UserDaoTest.class)

常用配置

#将等级为DEBUG的日志信息输出到console和file这两个目的地,console和file的定义在下面的代码 log4j.rootLogger=DEBUG,console,file
#控制台输出的相关设置 log4j.appender.console = org.apache.log4j.ConsoleAppender log4j.appender.console.Target = System.out log4j.appender.console.Threshold=DEBUG log4j.appender.console.layout = org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern=[%c]-%m%n
 #文件输出的相关设置 log4j.appender.file = org.apache.log4j.RollingFileAppender log4j.appender.file.File=./log/kuang.log log4j.appender.file.MaxFileSize=10mb log4j.appender.file.Threshold=DEBUG log4j.appender.file.layout=org.apache.log4j.PatternLayout log4j.appender.file.layout.ConversionPattern=[%p][%d{yy-MM-dd}][%c]%m%n
 #日志输出级别 log4j.logger.org.mybatis=DEBUG log4j.logger.java.sql=DEBUG log4j.logger.java.sql.Statement=DEBUG log4j.logger.java.sql.ResultSet=DEBUG log4j.logger.java.sql.PreparedStatement=DEBUG

注解

原文地址:https://www.cnblogs.com/2506236179zhw/p/14926394.html