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  • 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

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