SQL与Oracle中的group by区别开来

Question

我有以下SQL：

select 
  origin,destination,to_char(to_date(substr(ship_date,1,6),'YYMMDD'),
  'YYYY-MM-DD'),ship_date,trip_number, distinct ship_number  
from shipment a 
where 
  a.scc_code in ('xxxxx','xxxxx','xxxxx') 
  and load_status = 'S' and ship_date like '11%' 
  and shipper_id = XXXXXX
group by origin,destination,ship_date,trip_number, ship_number

当我在Oracle中运行此SQL时，它给出了ORA-00936：缺少表达式。 如果我删除distinct关键字，它运行正常。 谁能告诉我这两件事之间的区别？

Answer 1

不同的关键字适用于所有选定的列，因此您必须在选择之前放置它

select distinct 
  origin,destination,to_char(to_date(substr(ship_date,1,6),'YYMMDD'),
  'YYYY-MM-DD'),ship_date,trip_number, ship_number  
from shipment a 
where 
  a.scc_code in ('xxxxx','xxxxx','xxxxx') 
  and load_status = 'S' and ship_date like '11%' 
  and shipper_id = XXXXXX
group by origin,destination,ship_date,trip_number, ship_number