[大数据]Java-Mybatis核心配置

Java-Mybatis核心配置

• mybatis-config.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>
      <!-- 加载外部配置文件 -->
      <properties resource="jdbc.properties"/>
      
      <!-- 设置 -->
      <settings>
          <!-- 开启日志：STDOUT_LOGGING | LOG4J -->
          <setting name="logImpl" value="STDOUT_LOGGING"/>
      </settings>
      
      <!-- 类型别名 -->
      <typeAliases>
          <!--<typeAlias type="cn.cnyasin.pojo.User" alias="User"/>-->
          <package name="cn.cnyasin.pojo"/>
      </typeAliases>
      
      <environments default="development">
          <environment id="development">
              <transactionManager type="JDBC"/>
              <dataSource type="POOLED">
                  <property name="driver" value="${jdbc.driverClassName}"/>
                  <property name="url" value="${jdbc.url}"/>
                  <property name="username" value="${jdbc.username}"/>
                  <property name="password" value="${jdbc.password}"/>
              </dataSource>
          </environment>
      </environments>
      
      <mappers>
          <!-- 每一个Mapper.xml都要在Mybatis核心配置文件中注册！ -->
          <mapper resource="cn/cnyasin/dao/UserMapper.xml"/>
          <!--<mapper class="cn.cnyasin.dao.UserMapper"/>--><!-- 此写法要求mapper和mapper.xml必须同名且在一个目录 -->
          <!--<mapper url="file:///var/mappers/UserPapper.xml"/>--><!-- 不推荐 -->
      </mappers>
      
  </configuration>
  

• 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">
  <!-- 一个namespace对应一个Mapper类（原来的dao） -->
  <mapper namespace="cn.cnyasin.dao.UserMapper">
      <!--
      id：一个id对应一个方法
      resultType：返回一个结果
      resultMap：返回多个结果
      -->
      <select id="getOne" resultType="cn.cnyasin.pojo.User">
          select * from user where id = #{id}
      </select>
      <insert id="addOne" parameterType="cn.cnyasin.pojo.User">
          insert into user (`username`,`email`,`password`,`created_at`) values (#{username}, #{email}, #{password}, #{created_at})
      </insert>
      <update id="updateOne" parameterType="cn.cnyasin.pojo.User">
          update user set balance = #{balance} where id = #{id};
      </update>
      <delete id="deleteOne">
          delete from user where id = #{id}
      </delete>
      <resultMap id="userListMap" type="cn.cnyasin.pojo.User"/>
  </mapper>