在sybase數據庫中有這樣三個table1(year,month,vendor,amt) table2(vendor,name,venclass) table3(venclass,description) 現在我想得到的結果為: year, venclass,description,1月amt,2月amt......12月amt 這些結果要以year,venclass分組合計得來的. 互相幫助,共同進步

------
互相幫助,共同進步

可以這樣下:

select year, t2.venclass, description,
  sum(case when month=1 then amt else 0 end) as "1月amt",
  sum(case when month=2 then amt else 0 end) as "1月amt",
  sum(case when month=3 then amt else 0 end) as "1月amt",
  ...
  sum(case when month=12 then amt else 0 end) as "12月amt",
from table1 t1 
  inner join table2 t2 on t1.vendor=t2.vendor
  inner join table3 t3 on t2.venclass=t3.venclass
group by year, t2.venclass, description
order by year, t2.venclass

引言: 可以這樣下:

select year, t2.venclass, description,
  sum(case when month=1 then amt else 0 end) as "1月amt",
  sum(case when month=2 then amt else 0 end) as "1月amt",
  sum(case when month=3 then amt else 0 end) as "1月amt",
  ...
  sum(case when month=12 then amt else 0 end) as "12月amt",
from table1 t1 
  inner join table2 t2 on t1.vendor=t2.vendor
  inner join table3 t3 on t2.venclass=t3.venclass
group by year, t2.venclass, description
order by year, t2.venclass

但是會出現語法錯誤,inner附近的語法錯,是不是在sybase中不能這樣用? 錯誤提示:Incorrect syntax near 'inner'. 互相幫助,共同進步

[quote] 可以這樣下:

select year, t2.venclass, description,
  sum(case when month=1 then amt else 0 end) as "1月amt",
  sum(case when month=2 then amt else 0 end) as "1月amt",
  sum(case when month=3 then amt else 0 end) as "1月amt",
  ...
  sum(case when month=12 then amt else 0 end) as "12月amt", -- 最後一個逗號要拿掉
from table1 t1 
  inner join table2 t2 on t1.vendor=t2.vendor
  inner join table3 t3 on t2.venclass=t3.venclass
group by year, t2.venclass, description
order by year, t2.venclass

若還是不行的話就將 from 的後面改為:

from table1 t1, table2 t2, table3 t3 
where t1.vendor=t2.vendor and t2.venclass=t3.venclass
group by year, t2.venclass, description
order by year, t2.venclass