Oracle PL-SQL中模糊定义的列

Question

我试图在不同的表上选择多行,但无论我做什么,我都无法工作.我收到此错误:

Error(14,1): PL/SQL: ORA-00918: column ambiguously defined

代码(注意,这是触发器的一部分,这就是为什么:new):

SELECT brw.borage, bt.agelower, bt.ageupper
INTO borAge, minAge, maxAge
FROM Borrower brw, BookTitle bt
  INNER JOIN BookCopy bc ON  :new.bcID = bc.bcID
  INNER JOIN BookTitle bt ON bt.isbn = bc.isbn

注意:BookTitle只有一个ageLower和ageUpper列.除了borAge,minAge和maxAge之外,没有任何变化.

Answer 1

Tre问题是你有两次相同的别名,试试这个:

SELECT brw.borage, bt.agelower, bt.ageupper
INTO borAge, minAge, maxAge
FROM Borrower brw, BookTitle bt
  INNER JOIN BookCopy bc ON  :new.bcID = bc.bcID
  INNER JOIN BookTitle bt2 ON bt2.isbn = bc.isbn

但是这可以为您提供比预期更多的结果,因为您将BookTitle表放在FROM部分上.

我认为只有这可能是你真正需要的:

SELECT brw.borage, bt.agelower, bt.ageupper
INTO borAge, minAge, maxAge
FROM Borrower brw
  INNER JOIN BookCopy bc ON  :new.bcID = bc.bcID
  INNER JOIN BookTitle bt ON bt.isbn = bc.isbn