sql - Oracle 外连接 "entity"

Question

如何在查询中引用从外部联接创建的“组合实体”？具体来说，如何替换“??”在下面的查询中:

SELECT TableA.x, 
       ??.y --How do you select from the combined entity?
  FROM TableA, 
       TableB buys 
FULL OUTER JOIN TableB sells ON buys.run_id = sells.run_id 
                            AND buys.specie_id = sells.specie_id 
                            AND buys.account_id = sells.account_id
WHERE TableA.id = ?? 
  AND -- want to join this with the "combined entity" resulting from the outer join
      buys.buy = 'Y' 
  AND -- Is this valid or does this have to be within the Outer join statement?
      sells.buy = 'N';

Answer 1

select TableA.x, fullTable.y 
from TableA 
  INNER JOIN
    ( SELECT y
        FROM TableB buys
          full outer join TableB sells
            on buys.run_id = sells.run_id
            and buys.specie_id = sells.specie_id
            and buys.account_id = sells.account_id
            AND buys.buy = 'Y' AND sells.buy = 'N'    
    ) AS fullTable
    ON TableA.id = fullTable.y

---

条件可以是最终的WHERE或ON像这样，但它本质上取消了完整的连接:

select TableA.x, fullTable.y 
from TableA 
  INNER JOIN
    ( SELECT y
           , buys.buy AS buysBuy             --- fields here so they can be
           , sells.buy AS sellsBuy           --- used in the final WHERE or ON
        FROM TableB buys
          full outer join TableB sells
            on buys.run_id = sells.run_id
            and buys.specie_id = sells.specie_id
            and buys.account_id = sells.account_id                
    ) AS fullTable
    ON TableA.id = fullTable.y
    AND buysBuy = 'Y' AND sellsBuy = 'N'    --- the condition here