Mybatis笔记1

<!--
命名空间：区分不同表的id
 -->
<mapper namespace="test">
 
  <!-- 通过id查询一个用户 -->
  <select id="findUserById" parameterType="Integer" resultType="com.caiyilan.pojo.User">
      select *from user where id=#{v}
 
  </select>
 
  <!-- 模糊查询
   #{}      select *from user where id=? 占位符
   ${value}      select *from user where username like      字符串拼接
   -->
  <select id="findUserByUsername" parameterType="String" resultType="com.caiyilan.pojo.User">
      <!-- select *from user where username like '%${value}%'  value 为固定值-->
      <!-- 最终版本,防止SQL注入，使用#{}占位符 -->
      select *from user where username like "%"#{haha}"%"
 
  </select>
  <!-- 添加用户 -->
  <insert id="insertUser" parameterType="com.caiyilan.pojo.User">
  insert into user(username,birthday,address,sex)
  values(#{username},#{birthday},#{address},#{sex})
 
 
 
  </insert>