Subquery with invalid identifier error in sql

问题

want to select tour date and site names in advance of total cost is more than 230 and that tour has more than 7 persons. the complete code is below, the first part of union works.

SELECT tour_date AS "Departure Date",  site_name "Site Name"
FROM partres, reservation, tour, site
WHERE partres.res_id = reservation.res_id
  AND reservation.tour_id = tour.tour_id
  AND tour.site_id = site.site_id
GROUP BY tour_date, site_name
HAVING COUNT(part_id) > 7

  UNION

SELECT tour_date AS "Departure Date",  site_name "Site Name"
FROM (
  SELECT res_id,tour_date,site_name, (res_partcost +NVL(RES_GEARCOST,0)) as "total_cost" 
  FROM reservation,site,tour) 
WHERE  reservation.tour_id = tour.tour_id
  AND tour.site_id = site.site_id
  AND total_cost > 230
GROUP BY tour_date, site_name;

I still got errors as

ORA-00904: "TOTAL_COST": invalid identifier
00904. 00000 -  "%s: invalid identifier"
*Cause:    
*Action:
Error at Line: 437 Column: 7

Thanks

回答1:

You need to move your join conditions inside the subquery

SELECT tour_date AS "Departure Date",  site_name "Site Name"
FROM (
    SELECT res_id,tour_date,site_name, (res_partcost +NVL(RES_GEARCOST,0)) as "total_cost" 
    FROM reservation,site,tour
    WHERE reservation.tour_id = tour.tour_id
    AND tour.site_id = site.site_id ) Res1
WHERE Res1.total_cost > 230 // this will not be displayed in a result
GROUP BY tour_date, site_name;

回答2:

A union is not going to give you an "and" between the conditions. It is going to give you an "or" (because anything that matches either condition will be included).

I think you should phrase this as a single query, with subqueries. Also, proper join syntax is a benefit:

SELECT tour_date AS "Departure Date",  site_name "Site Name"
FROM partres p join
     reservation r
     on p.res_id = r.res_id join
     tour t
     on r.tour_id = t.tour_id and
        (res_partcost + coalesce(RES_GEARCOST,0)) > 230 join
     site s
     on t.site_id = s.site_id
GROUP BY tour_date, site_name
having COUNT(part_id) > 7;

This version is making a guess that total_cost is in the reservation table.

来源：https://stackoverflow.com/questions/16825262/subquery-with-invalid-identifier-error-in-sql

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sql

Oracle

subquery