一对一

<sql id="column">
   a.id id,
   a.order_id orderId,
   a.customer_no customerNo,
   a.nums nums,
   a.state state,
   DATE_FORMAT(a.create_time,'%Y-%m-%d %H:%i:%S')  createTime,
   a.create_no createNo,
   DATE_FORMAT(a.update_time,'%Y-%m-%d %H:%i:%S') updateTime,
   a.update_no updateNo
</sql>

<select id="findOrderInfosUserResultMap" resultMap="orderInfosUserResultMap">
  SELECT
  <include refid="column"/>,
  b.id customerId,
  b.customer_name customerName,
  b.birthday birthday,
  b.sex sex,
  b.address address,
  b.create_time customerCreateTime,
  b.create_no customerCreateNo,
  b.update_time customerUpdateTime,
  b.update_no customerUpdateNo
  FROM order_info a , customer b WHERE a.customer_no = b.customer_no
</select>

<resultMap id="orderInfosUserResultMap" type="com.chenfh.mybatis.springbootmybatis.dto.OrdersRelevanceDto">

  <!-- Column: 订单信息(order_info)的唯一标识列; property: 订单信息的唯一标识列映射到OrdersRelevanceDto类中的那个属性-->
  <id column="id" jdbcType="INTEGER" property="id"/>
  <result column="order_id" jdbcType="INTEGER" property="orderId"/>
  <result column="customerNo" jdbcType="INTEGER" property="customerNo"/>
  <result column="nums" jdbcType="INTEGER" property="nums"/>
  <result column="state" jdbcType="INTEGER" property="state"/>
  <result column="createTime" jdbcType="VARCHAR" property="createTime"/>
  <result column="createNo" jdbcType="VARCHAR" property="createNo"/>
  <result column="updateTime" jdbcType="VARCHAR" property="updateTime"/>
  <result column="updateNo" jdbcType="VARCHAR" property="updateNo"/>
  <!-- 配置映射相关联的用户信息; association: 用于关联映射关系查询单个对象的信息;
    property:要将关联查询的用户信息映射到OrdersRelevanceDto中的那个属性-->
  <association property="customerDto" javaType="com.chenfh.mybatis.springbootmybatis.dto.CustomerDto">
    <!-- id: 关联查询用户的唯一标识; column: 指定唯一标识用户信息的列; property: 映射到CustomerDto的那个属性 -->
    <id column="customerNo" property="customerNo"/>
    <result column="customerId" jdbcType="INTEGER" property="id"/>
    <result column="customerName" jdbcType="VARCHAR" property="customerName"/>
    <result column="birthday" jdbcType="VARCHAR" property="birthday"/>
    <result column="sex" jdbcType="CHAR" property="sex"/>
    <result column="address" jdbcType="VARCHAR" property="address"/>
    <result column="customerCreateTime" jdbcType="TIMESTAMP" property="createTime"/>
    <result column="customerCreateNo" jdbcType="VARCHAR" property="createNo"/>
    <result column="customerUpdateTime" jdbcType="TIMESTAMP" property="updateTime"/>
    <result column="customerUpdateNo" jdbcType="VARCHAR" property="updateNo"/>
  </association>

</resultMap>