MIT-Curricular/DBMS/SQL/Week6/writeup.md

1. Create a function to return total number of accidents happened in a particular year.

SQL> create or replace function total_accd
    (year in int)
    return int
    as
    total int;
    begin
    select count(report_number)
    into total
    from accident
    where extract(year from accd_date)=year;
    return total;
    end;
    /

Function created.

SQL> select total_accd(2024) from dual;

TOTAL_ACCD(2024)
----------------
               2

2. Create a procedure to display total damage caused due to an accident for a particular driver on a specific year.

create or replace procedure tot_damage
  (driver in varchar2, year in number) is
  damage number := 0;  
begin
  select sum(damage_amount) into damage
  from participated pa
  natural join accident ac
  where pa."driver_id#" = driver  
  with quotes
    and extract(year from ac.accd_date) = year;

  dbms_output.put_line('total damage: ' || nvl(damage, 0));
exception
  when no_data_found then
    dbms_output.put_line('no data found for the given driver and year.');
  when others then
    dbms_output.put_line('an error occurred: ' || sqlerrm);
end;
/

SQL> execute tot_damage('1236',2024);
Total damage: 150

PL/SQL procedure successfully completed.

3. Create a procedure to display accident information which took place in a particular location.

SQL> create or replace procedure accident_info(location_value in varchar) IS
  begin
        for accident_rec in
       (select * from accident where location = location_value) loop
            dbms_output.put_line('Report Number: ' || accident_rec.report_number || ', Date: ' || accident_rec.accd_date || ', Location: ' || accident_rec.location);
       end loop;
    end;
    /

SQL> execute accident_info('Delhi India');
Report Number: 1, Date: 01-JAN-24, Location: Delhi India

PL/SQL procedure successfully completed.

4. Create a procedure to identify all drivers who have never been involved in any accidents. The procedure should return their driver-id, name, and address.

SQL> CREATE OR REPLACE PROCEDURE GetDriversWithoutAccidents AS
    begin
        for rec in (
            select p.driver_id#, p.name, p.address
            from person p
            left join participated pa on p.driver_id# = pa.driver_id#
            where pa.report_number is null
        ) loop
            dbms_output.put_line('driver id: ' || rec.driver_id# ||

                                 ', name: ' || rec.name ||
                                 ', address: ' || rec.address);
        end loop;
    end;
    /

Procedure created.

SQL> EXEC GetDriversWithoutAccidents;
Driver ID: 1237, Name: Saarthak, Address: Manipal India
Driver ID: 1235, Name: Rohit, Address: Banglalore India

PL/SQL procedure successfully completed.

Q5. Write a function that takes a REGNO as input and returns the total number of accidents in which the car was involved

SQL> create or replace function gettotalaccidentsbyregno(p_regno in varchar2)
    return number
    is
        v_total_accidents number;
    begin
        select count(*)
        into v_total_accidents
        from participated
        where regno = p_regno;
        return v_total_accidents;
    exception
        when no_data_found then
            return 0;
        when others then
            raise;
    end;
    /

Function created.

SQL> SELECT GetTotalAccidentsByRegno('ABCD0001') AS Total_Accidents
  2  FROM dual;

TOTAL_ACCIDENTS
---------------
              1