WITH AS短语，也叫做子查询部分（subquery factoring）

可以让你做很多事情，定义一个SQL片断，该SQL片断会被整个SQL语句所用到。

作为提供数据的部分。

代码例子：

with temp as
 (select ID, Type_Name, Type_ID
    from T_Base_GoodsType as t
   where t.Shop_ID = @shop_id
     and Type_ID = @Goods_TypeID
  union all
  select t1.ID, t1.Type_Name, t1.Type_ID
    from T_Base_GoodsType as t1
   inner join temp
      on t1.ParentType_ID = temp.Type_ID
   where t1.Shop_ID = @shop_id)
select *
  from (select Stock_Amount,
               S.StockWarn_Amount,
               S.All_Amount,
               G.Goods_ID,
               G.Goods_Name,
               G.Goods_Unit,
               ROW_NUMBER() over(order by Stock_Amount desc) as rowid
          from T_IM_StockInfo as S
         inner join T_Base_GoodsInfo AS G
            on S.Goods_ID = G.Goods_ID
         inner join temp
            on temp.Type_ID = G.Goods_TypeID
         where S.Shop_ID = @shop_id
           AND G.Shop_ID = @shop_id
           and G.Goods_TypeID = temp.Type_ID
         group by S.Stock_Amount,
                  S.All_Amount,
                  G.Goods_ID,
                  G.Goods_Name,
                  G.Goods_Unit,
                  S.StockWarn_Amount
        HAVING SUM(S.Stock_Amount) < S.StockWarn_Amount) m
 WHERE rowid between @pageindex and @pagesize

参考：sql with as 用法