Schreiben Auslöser einer Tabelle automatisch eine andere Tabelle zu aktualisieren

Question

ich diese Tabellen bekam (Oracle):

Doctors (Doctor_ID (PK), 
     Doctor_Name, 
     DoB, 
     Specialization) 

Doctors_At_Work (Doctor_ID (PK), 
       The_Date (PK), 
       Hour_Start (PK), 
       Hour_Stop, 
       Room) 

Consultations_Intervals (Doctor_ID (PK), 
         The_Date (PK), 
         Start_Hour_Consult (PK), 
         Stop_Hour_Consut, 
         Room) 

OBS: A consultation last for only 30 minutes. 

Meine Aufgabe ist es, die notwendigen Trigger erstellen (insert/update/delete) von Doctors_At_Work, um automatisch zu aktualisieren die Consultations_Intervals Tabelle.

Was ich bisher tat:

Create sequence seq_id_doctor START with 1 INCREMENT BY 1 ORDER NOCACHE; 

CREATE OR REPLACE trigger t_1 
     BEFORE INSERT ON Doctors_At_Work FOR EACH ROW 
BEGIN 
    :NEW.Doctor_ID:=seq_id_doctor.NextValue; 
    :NEW.The_Date:=CURRENT_TIMESTAMP; 
    :NEW.Hour_Start:=Select Extract (Hour from CURRENT_TIMESTAMP); 
END; 
/

CREATE OR REPLACE trigger t_2 
     AFTER INSERT OR UPDATE ON Consultations_Intervals FOR EACH ROW 
BEGIN 
INSERT INTO Consultations_Intervals VALUES 
(:NEW.Doctor_ID, :NEW.The_Date, :NEW.Hour_Start, :NEW.Hour_Start + 
    interval '30' minute, :NEW.Room); 
END; 
/

was falsch ist? Wie soll ich diese Aufgabe lösen? (wenn es andere Ideen gibt)

Answer 1

Alles, was Sie brauchen, ist ein einfacher Trigger auf Ihrer Doctors_At_work Tabelle. Siehe Beispiel unten:

Tables:

create table Doctors_At_Work (Doctor_ID number Primary key, 
       The_Date date , 
       Hour_Start date  , 
       Hour_Stop date, 
       Room number); 

create table Consultations_Intervals (Doctor_ID number, 
         The_Date date , 
         Start_Hour_Consult number, 
         Stop_Hour_Consut number, 
         Room number); 

Trigger:

create or replace trigger t_1 
    before insert or update or delete on doctors_at_work 
    for each row 
begin 
    insert into consultations_intervals (doctor_id, 
             the_date, 
             start_hour_consult, 
             stop_hour_consut, 
             room) 
     values (:new.doctor_id, 
       current_timestamp, 
       extract (minute from current_timestamp), 
       extract (minute from current_timestamp), 
       :new.room); 
end; 
/

Ausgang:

SQL> Prompt "Before trigger" 
"Before trigger" 

SQL> select * from Doctors_At_Work; 

no rows selected 

SQL> select * from Consultations_Intervals; 

no rows selected 

SQL> create or replace trigger t_1 
    before insert or update or delete on doctors_at_work 
    2 3  for each row 
    4 begin 
    insert into consultations_intervals (doctor_id, 
    5 6           the_date, 
    7           start_hour_consult, 
    8           stop 
    . 
    . 
    . 
Trigger created. 

SQL> Insert into DOCTORS_AT_WORK 
    (DOCTOR_ID, THE_DATE, HOUR_START, HOUR_STOP, ROOM) 
Values 
    (2, TO_DATE('12/18/2016 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), TO_DATE('12/13/2016 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), TO_DATE('12/14/2016 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 12); 
COMMIT; 
    2 3 4 
1 row created. 

SQL> 
Commit complete. 

SQL> select * from Doctors_At_Work; 

DOCTOR_ID THE_DATE HOUR_STAR HOUR_STOP  ROOM 
---------- --------- --------- --------- ---------- 
     2 18-DEC-16 13-DEC-16 14-DEC-16   12 

SQL> select * from Consultations_Intervals; 

DOCTOR_ID THE_DATE START_HOUR_CONSULT STOP_HOUR_CONSUT  ROOM 
---------- --------- ------------------ ---------------- ---------- 
     2 19-DEC-16     17    17   12