Question

我尝试了许多没有财富的解决方案。有人请帮忙

TABLE_1 ：

car_type date_purchased  down_payment
-------------------------------------
toyota    2/2012             $100
honda     4/2012             $500
ford      5/2012             $235
toyota    1/2013             $400
honda     4/2013             $20

Final_table （应该是这样的）：

car_type  date      final_cost
--------------------------------
toyota    3/2012      $100
honda     4/2012      $500
ford      12/2012     $235

最终表应该像这样创建：

update final_table
set final_cost = table_1.down_payment 
where final_table.car_type = table1.car_type 
  and max(table_1.date_purchased) <= final_table.date

费用应该是max(date_purchased)小于或等于final_table.date的费用

但是SQL Server不喜欢max和＆lt; = part。

它一直在说要添加和分组，但他们没有工作

有谁知道如何让代码工作？

格拉西亚斯

Answer 1

试试这个：

update final_table
set final_cost = table_1.down_payment 
where final_table.car_type = table1.car_type 
and final_table.date > (
  select max(date_purchased) from table_1)

Answer 2

我建议：

update ft
    set final_cost = t1.down_payment 
    from final_table ft outer apply
         (select top 1 t1.*
          from table_1 t1
          where t1.car_type = ft.car_type and
                t1.date_purchased <= ft.date
          order by t1.date_purchased desc
         ) t1;

Answer 3

你不能在哪里使用聚合函数！使用group by with。

update final_table
set final_cost = table_1.down_payment 
where final_table.car_type = table1.car_type 
and table_1.date_purchased in (select table_1.date_purchased from table_1 
 group by table_1.date_purchased
 having (max(table_1.date_purchased) <= final_table.date)
 )

使用聚合函数的SQL Update语句导致错误

3 个答案: