SQL - 复杂的 SQL 查询

Question

I have two tables; the first one is order with columns doc_num, doc_type, doc_tttc , and the second one is order details with columns doc_num, doc_origi, art_code, art_des, qte, price - see below:

Clarification: order with DAC type is order taken by the client and the order with DAA type is order taken by the supervisor is the same order in some cases but the supervisor can change the amount 'QTE' or the item 'ART_CODE' for that's way I want to show as result:

DAC-19001    DAA-19001  1200    1500

 ART3         ART3        1      300

Answer 1

Welcome to S/O. Not sure exactly what your intent / need is, but maybe this will help. Since your order table has the detail totals already aggregated, you probably need to join based on their being a match to a supervisor order by the original document number.

Not sure why the "ART3" values were coming along from details... no basis of why one record vs another on that field.

However, here is what I have. The primary query from the order table gets orders. No problem. Then, a LEFT-JOIN means look IF there is a record that matches based on the join criteria. In this inner "od" result alias query, I am getting distinct original document orders and corresponding supervisor order just for the ID reference. Then, if so found, re-joining back to the order table to get ITS total amount by that document number. I could have also done an aggregation of the details and skipped the last left-join. This could also get the last ART code, but since no ID, record ID, "last record" basis, I would just leave that part alone for now.

select
      o.Doc_Num,
      o.Doc_Type,
      o2.Doc_Num as Supervisor_Doc_Num,
      o.Doc_TTC as OriginalOrderTotal,
      o2.Doc_TTC as SupervisorOrderTotal,
      o2.Doc_TTC - o.Doc_TTC as OrderDifference
   from
      Order o
         LEFT JOIN 
         ( select distinct 
                 Doc_OrigI,
                 Doc_Num
              from 
                 Order_Details ) od
            on o.Doc_Num = od.Doc_OrigI
            LEFT JOIN Order o2
               on od.Doc_Num = o2.Doc_Num