SQL错误:ORA-00918:列模糊定义

Question

请帮我看看我在这里做错了什么:

从第1行开始出错:命令中为1 -

CREATE VIEW VW_ROUTE AS
  SELECT ROUTE_NAME
       , FARE
       , DESTINATION
       , ROUTE_ID
       , STOP_NAME
       , TERMINUS
       , NUMBER_OF_STOPS
  FROM STOPS S
    LEFT JOIN ROUTE R
        ON S.ROUTE_ID = R.ROUTE_ID
 WHERE NUMBER_OF_STOPS > ('1')

Error at Command Line : 5 Column : 10
Error report -
SQL Error: ORA-00918: column ambiguously defined
00918. 00000 -  "column ambiguously defined"
*Cause:    
*Action:

Answer 1

两个表中都有相同的列名.添加别名.

CREATE VIEW VW_ROUTE AS
SELECT ROUTE_NAME
       , FARE
       , DESTINATION
       , S.ROUTE_ID          -- ROUTE_ID exists in table STOPS/ROUTE
       , STOP_NAME
       , TERMINUS
       , NUMBER_OF_STOPS
FROM STOPS S
LEFT JOIN ROUTE R
  ON S.ROUTE_ID = R.ROUTE_ID
WHERE NUMBER_OF_STOPS > ('1');

好的做法是在所有出现时使用别名以避免歧义.