Group by in query

Question

Hi!
We have a flight route table that holds individual flight legs together that build a route:
CREATE TABLE "TEST"."ROUTE"
   (     "ROUTE_ID" NUMBER NOT NULL ENABLE,
     "ORIGIN" VARCHAR2(3 BYTE) NOT NULL ENABLE,
     "DESTINATION" VARCHAR2(3 BYTE) NOT NULL ENABLE,
     "FLIGHT_LEG_ID" NUMBER NOT NULL ENABLE,
     "SEGMENT_ID" NUMBER NOT NULL ENABLE,
      CONSTRAINT "ROUTE_PK" PRIMARY KEY ("ROUTE_ID", "FLIGHT_LEG_ID", "SEGMENT_ID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
  TABLESPACE "USERS"  ENABLE
   ) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
  TABLESPACE "USERS" ;
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (1,'FCO','ZRH',9,1);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (1,'ZRH','JFK',10,2);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (2,'JFK','ZRH',11,1);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (2,'ZRH','FCO',12,2);The flight legs must be grouped by route_id. I.e. A user wants to go from Rome to New York, so the results must return both legs:
FCO  ZRH
ZRH  JFKThanks for your feedback!

Answer 1

This one, too. more test data:
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (3,'STG','FRA',19,1);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (3,'FRA','HKG',20,2);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (3,'HKG','MAN',21,3);
Insert into ROUTE (ROUTE_ID,ORIGIN,DESTINATION,FLIGHT_LEG_ID,SEGMENT_ID) values (3,'MAN','PMO',22,4);And the query
SQL>SELECT route_id, origin, destination, route
  2    FROM (SELECT route_id, origin, destination, MAX(route) OVER(PARTITION BY route_id) AS route
  3            FROM (SELECT     route_id, origin, destination, flight_leg_id, segment_id,
  4                             LTRIM(SYS_CONNECT_BY_PATH(origin, '-'), '-') || '-' || destination AS route
  5                        FROM route
  6                  CONNECT BY route_id = PRIOR route_id AND origin = PRIOR destination
  7                  START WITH origin = :origin))
  8   WHERE route LIKE :origin || '%' AND route LIKE '%' || :destination;
  ROUTE_ID ORIGI DESTI ROUTE
         3 STG   FRA   STG-FRA-HKG-MAN-PMO
         3 FRA   HKG   STG-FRA-HKG-MAN-PMO
         3 HKG   MAN   STG-FRA-HKG-MAN-PMO
         3 MAN   PMO   STG-FRA-HKG-MAN-PMOUrs