SQL Server: hata MSG 102 ve MSG 156

Question

Lütfen bana yardım edin. Ben sorgu

with cte as 
( 
    select 
     *, 
     row_number() over (partition by product order by date desc) as rownumber 
    from 
     saleslist 
    where 
     datediff(month, date, getdate()) < 2 
    ) 
    select 
     product, 
     ((max(case when rownumber = 1 then price end) - 
      max(case when rownumber = maxn then price))/
      max(case when rownumber = maxn then price end) 
     ) 
    from 
     (select cte.*, max(rownumber) over (partition by product) as maxn 
     from cte) 
group by product 

yazdım ve şu mesajları

Msg 102, Düzey 15, State 1

, Hat 13
yanlış sözdizimi yakın ')' aldık.

Msg 156, Düzey 15, Durum 1, Satır 18 'Grup' anahtar kelimesinin yakınında yanlış sözdizimi.

Birisi lütfen bunu nasıl düzeltebileceğimizi söyler misiniz?

Answer 1

with cte as 
( 
    select *, 
    row_number() over (partition by product order by date desc) as rownumber 
    from saleslist 
    where datediff(month, [date], getdate()) < 2 
    ) 
select product, 
    (
    (max(case when rownumber = 1 then price end) - 
     max(case when rownumber = maxn then price end) --< missing end here 
     )/
     max(case when rownumber = maxn then price end) 
     ) 
from 
(select cte.*, max(rownumber) over (partition by product) as maxn 
    from cte) t --< needs an alias here 
group by product 

Answer 2

Alt sorgu için bir tablo diğer adı gerekir. Ancak, sorgunuz aşırı karmaşık. Maksimum satır sayısı satır count(*) geçerli:

with cte as ( 
     select sl.*, 
      row_number() over (partition by product order by date desc) as rownumber, 
      count(*) over (partition by product) as maxrn 
     from saleslist sl 
     where datediff(month, date, getdate()) < 2 
    ) 
select product, 
    (
    (max(case when rownumber = 1 then price end) - 
     max(case when rownumber = maxn then price) 
     )/
     max(case when rownumber = maxn then price end) 
     ) 
from cte 
group by product; 

Answer 3

SQL server 2014 İLK ​​/ last_value

with cte as 
    ( 
     select *, 
      product, 
      price as first_price, 
      row_number() over (partition by product order by date) as rownumber, 
      last_value(price) -- price of the row with the latest date 
      over (partition by product 
       order by date rows 
       rows between unbounded preceding and unbounded following) as last_price 
      count(*) over (partition by product) as maxrn 
     from saleslist sl 
     where datediff(month, date, getdate()) < 2 
    ) 
select product, 
     (last_price - first_price)/first_price 
from cte 
where rownumber = 1;