mybaitis 的 mapper.xml 文件中 参数为List集合SQL 的写法。

1、应用场景：

传参：

MaterialCodeList， activity_end_time，userCode

具体SQl：

 <if test> 的验证： "MaterialCodeList != null and MaterialCodeList.size()>0"

<foreach > 循环： 循环体：item  序号：index 集合：collection  分割符：separator

<select id="selectPreDiscountInfoByErpCodeAndMaterialCode"  resultMap="BaseResultMap">

  SELECT ps.MATERIAL_CODE,ps.`NAME`,ps.DISCOUNT_AMOUNT  from pre_discount_sku ps where ps.pre_discount_id in(
  select pd.id from pre_discount pd where pd.discount_status = '1' and   pd.user_code =  #{userCode,jdbcType=VARCHAR} and to_days(pd.activity_end_time) >= to_days(now())
  )

  <if test="MaterialCodeList != null and MaterialCodeList.size()>0">
  and ps.material_code in(
  <foreach item="item" index="index" collection="MaterialCodeList" separator=",">
    #{item}
  </foreach>
  )
  </if>
</select>