Getting the last 5 records

Question

I was told I should do this by date, and not buy a number. He might still be right that by date is better. But I thought that by ticketnr makes also sense, because the latest ticket, is wel normally the most recent one. I've added the check although it might not be needed, so I may remove it later.
The idea behind it is that if, although a field that needs to be filled in would give an error if not being so, a field that needs to be filled in, isn't then that record can't be used. As that wouldn't be the case, I can remove that as well. That would make it less complex.
The idea was that records could have been deleted, so that you get 1185 1187 1188 1189 1190 . If you just take the 5 highest ticket numbers, you would only get 4 as one is missing. So I thought that if you include a check that check if the ticketid actually used or not. I suppose it would be nicer if one could write something similar to but therefore not the same:
if tikcetid(select ticketid into ticketidtotest from ticket where ticketid=tussenticketid;).used() = TRUE then;
Then you would be sure it is used, and it would just pick out the last 5 ones. There could be a problem with the dates if they are mixed up, but this could be a problem not just for this. So I think it would deserve a solution on the database.
I'm getting one error as it is now.
Error report:
ORA-06550: line 83, column 20:
PLS-00103: Encountered the symbol "=" when expecting one of the following:
. ( * @ % & = - + < / > at in is mod remainder not rem then
<an exponent (**)> <> or != or ~= >= <= <> and or like
between || multiset member SUBMULTISET_
06550. 00000 - "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.
*Action:
This is about the last : Tussen_ticketid := Tussen_ticketid - 1; But isn't it normall like it stands there ?
DECLARE
Mrecent_ticket NUMBER;
Tussen_ticketid NUMBER;
Ticketid_Place2 NUMBER;
Ticketid_Place3 NUMBER;
Ticketid_Place4 NUMBER;
Ticketid_Place5 NUMBER;
Ticketid_Place1 NUMBER;
TestVeld VARCHAR2(2000);
Query_to_use VARCHAR2(4000) := ' SELECT ticketid, applicatiecd, '||
' categorieid, titel, klantprioriteitid, interneprioriteitid, gebruikerid, statusid,'||
' versieid FROM ticket WHERE ticketid =';
Start_Rec_ticketid NUMBER;
TestVeldFoundThatIsCorrect NUMBER; is NULL; BOOLEAN := FALSE;
BEGIN
-- TestVeldFoundThatIsCorrect := FALSE;
     SELECT Max(Ticketid) INTO Mrecent_ticket FROM Ticket ;
     Tussen_ticketid := Mrecent_ticket;
     -- of dit echt nodig is weet ik zo niet
     -- kan eventueel opgevangen worden in de hoofd loop
     -- TestVeldFoundThatIsCorrect := FALSE;
     -- mischien checken op datum die ingevuld is, die moet ingevuld zijn wil het ok zijn
     LOOP From top to bottom  Till TEstVeldFOUNDTHATISCORRECT is TRUE
     WHILE TestVeldFoundThatIsCorrect != 9999999 LOOP
               SELECT titel INTO TestVeld FROM ticket WHERE ticketid =
               Tussen_ticketid;
          IF TestVeld is NULL THEN
               Tussen_ticketid := Tussen_ticketid - 1;
               TestVeld := NULL;
          ELSE
               TestVeldFoundThatIsCorrect := 9999999;
               Start_rec_ticketid := Tussen_ticketid;
               --Stop loop
          END IF;
     END LOOP;
     IF TestVeldFoundThatIsCorrect = 9999999 THEN
          Tussen_ticketid := Start_rec_ticketid;
          -- standaard is het onderstaande, bovenstaande gebeurt alleen als de bovenstaande loop
          -- gebruikt is
     ELSE
          Tussen_ticketid := Mrecent_ticket;
     END IF;
     -- mischien moet er nog een count gebeuren die kijkt hoeveel tickets er zijn in een bepaalde --
     -- periode en afhankelijk daarvan, tussen wanneer en wanneer een andere flag zetten
     --LOOP TELLER BETWEEN 1 AND  6
     While teller <= 5 LOOP
          SELECT titel INTO TestVeld FROM ticket WHERE ticketid = Tussen_ticketid;
          --Veld_dat_ingevuld_moet_zijn INTO  TestVeld FROM ticket WHERE ticketid = Tussen_ticketid;
          -- dit zou het datumveld moeten zijn
          IF TestVeld is NOT NULL THEN
               -- dan is dat record ok voor gebruik
               -- wel nog nakijken welke veld dat moet zijn, moet altijd ingevuld zijn
               -- waarde doet er niet toe
               --Query_to_use := Query_to_use || ' UNION SELECT ticketid, applicatiecd, '||
               --' categorieid, titel, klantprioriteitid, interneprioriteitid, gebruikerid, statusid,'||
               --' versieid FROM ticket WHERE ticketid = ';
               IF Teller = 1 THEN
Ticketid_place1 := Tussen_ticketid;
Query_to_use := Query_to_use || 'Ticketid_place1';
               ELSIF Teller = 2 THEN
Ticketid_place2 := Tussen_ticketid;
Query_to_use := 'UNION'||Query_to_use || 'Ticketid_place2';
               ELSIF Teller = 3 THEN
Ticketid_place3 := Tussen_ticketid;
Query_to_use := 'UNION'||Query_to_use || 'Ticketid_place3';
               ELSIF Teller = 4 THEN
Ticketid_place4 := Tussen_ticketid;
Query_to_use :='UNION'|| Query_to_use || 'Ticketid_place4';
               ELSIF Teller = 5 THEN
Ticketid_place5 := Tussen_ticketid;
Query_to_use :='UNION'|| Query_to_use || 'Ticketid_place5';
               ELSIF Teller = 6 THEN
                    Teller := Teller + 1;
               END IF;
               Teller := Teller + 1;
               Tussen_ticketid := Tussen_ticketid - 1;
          ELSIF
               Tussen_ticketid := Tussen_ticketid - 1;
          END IF;
     END LOOP;
     -- dbms_output.Put_line(Query_to_use);
     RETURN Query_to_use;
END;

Answer 1

DECLARE
Mrecent_ticket NUMBER;
Tussen_ticketid NUMBER;
Ticketid_Place2 NUMBER;
Ticketid_Place3 NUMBER;
Ticketid_Place4 NUMBER;
Ticketid_Place5 NUMBER;
Ticketid_Place1 NUMBER;
TestVeld VARCHAR2(2000);
Query_to_use VARCHAR2(4000) := ' SELECT ticketid,
applicatiecd, '||
' categorieid, titel, klantprioriteitid,
interneprioriteitid, gebruikerid, statusid,'||
' versieid FROM ticket WHERE ticketid =';
Start_Rec_ticketid NUMBER;
TestVeldFoundThatIsCorrect NUMBER; --is NULL;
--BOOLEAN := FALSE;
EGIN
-- TestVeldFoundThatIsCorrect := FALSE;
Max(Ticketid) INTO Mrecent_ticket FROM Ticket ;
ussen_ticketid := Mrecent_ticket;
     -- of dit echt nodig is weet ik zo niet
     -- kan eventueel opgevangen worden in de hoofd loop
     -- TestVeldFoundThatIsCorrect := FALSE;
-- mischien checken op datum die ingevuld is, die
e moet ingevuld zijn wil het ok zijn
LOOP From top to bottom  Till
l TEstVeldFOUNDTHATISCORRECT is TRUE
     WHILE TestVeldFoundThatIsCorrect != 9999999 LOOP
SELECT titel INTO TestVeld FROM ticket WHERE
ERE ticketid =
               Tussen_ticketid;
          IF TestVeld is NULL THEN
               Tussen_ticketid := Tussen_ticketid - 1;
               TestVeld := NULL;
          ELSE
               TestVeldFoundThatIsCorrect := 9999999;
               Start_rec_ticketid := Tussen_ticketid;
               --Stop loop
          END IF;
     END LOOP;
     IF TestVeldFoundThatIsCorrect = 9999999 THEN
          Tussen_ticketid := Start_rec_ticketid;
-- standaard is het onderstaande, bovenstaande
de gebeurt alleen als de bovenstaande loop
          -- gebruikt is
     ELSE
          Tussen_ticketid := Mrecent_ticket;
     END IF;
-- mischien moet er nog een count gebeuren die kijkt
t hoeveel tickets er zijn in een bepaalde --
-- periode en afhankelijk daarvan, tussen wanneer en
n wanneer een andere flag zetten
     --LOOP TELLER BETWEEN 1 AND  6
     While teller <= 5 LOOP
SELECT titel INTO TestVeld FROM ticket WHERE
RE ticketid = Tussen_ticketid;
--Veld_dat_ingevuld_moet_zijn INTO  TestVeld FROM
OM ticket WHERE ticketid = Tussen_ticketid;
          -- dit zou het datumveld moeten zijn
          IF TestVeld is NOT NULL THEN
               -- dan is dat record ok voor gebruik
-- wel nog nakijken welke veld dat moet zijn, moet
oet altijd ingevuld zijn
               -- waarde doet er niet toe
--Query_to_use := Query_to_use || ' UNION SELECT
ECT ticketid, applicatiecd, '||
--' categorieid, titel, klantprioriteitid,
id, interneprioriteitid, gebruikerid, statusid,'||
               --' versieid FROM ticket WHERE ticketid = ';
               IF Teller = 1 THEN
Ticketid_place1 :=
Tussen_ticketid;
Query_to_use :=
Query_to_use || 'Ticketid_place1';
               ELSIF Teller = 2 THEN
Ticketid_place2 :=
Tussen_ticketid;
Query_to_use :=
'UNION'||Query_to_use || 'Ticketid_place2';
               ELSIF Teller = 3 THEN
Ticketid_place3 :=
Tussen_ticketid;
Query_to_use :=
'UNION'||Query_to_use || 'Ticketid_place3';
               ELSIF Teller = 4 THEN
Ticketid_place4 :=
Tussen_ticketid;
Query_to_use :='UNION'||
Query_to_use || 'Ticketid_place4';
               ELSIF Teller = 5 THEN
Ticketid_place5 :=
Tussen_ticketid;
Query_to_use :='UNION'||
Query_to_use || 'Ticketid_place5';
               ELSIF Teller = 6 THEN
                    Teller := Teller + 1;
               END IF;
               Teller := Teller + 1;
               Tussen_ticketid := Tussen_ticketid - 1;
          ELSIF
               Tussen_ticketid := Tussen_ticketid - 1;
          END IF;
     END LOOP;
     -- dbms_output.Put_line(Query_to_use);
     RETURN Query_to_use;
END;WHat are you trying to achive by this code? Please explain this bolded script part. I didn't see any function is using here. But, you are returning one value to where? Or may be i overlooked it. Please explain it.
Regards.
Satyaki De.