MIT-Curricular/DBMS/SQL/Week4/writeup.md

## Lab 4 - OracleDB

### Verifying the existence of the previous labs' DB.
```sql
SQL> select table_name from user_tables;

TABLE_NAME
--------------------------------------------------------------------------------
ACCIDENT
CAR
OWNS
PARTICIPATED
PERSON
```

### Q1. Find the total number of people who owned cars that were involved in accidents in 2008.

Ans. 

Modifying the table to add required entry from 2008.
```sql

SQL> select * from accident;

REPORT_NUMBER ACCD_DATE LOCATION
------------- --------- --------------------------------------------------
            1 01-JAN-24 Delhi India
            3 29-FEB-24  India
            5 31-MAR-00  Gujrat India
           12 17-JUL-00  karnataka India
           10 01-JAN-08 Manipal India

SQL> update accident set ACCD_DATE='01-Jan-2008' where REPORT_NUMBER=1
  2  ;

1 row updated.

SQL> select * from accident;

REPORT_NUMBER ACCD_DATE LOCATION
------------- --------- --------------------------------------------------
            1 01-JAN-08 Delhi India
            3 29-FEB-24  India
            5 31-MAR-00  Gujrat India
           12 17-JUL-00  karnataka India
           10 01-JAN-08 Manipal India
```


```sql
SQL> select count(distinct Driver_ID#) from participated natural join accident where extract(year from accd_date)=2008;

COUNT(DISTINCTDRIVER_ID#)
-------------------------
                        1
```

### Q2. Find the number of accidents in which cars belonging to a specific model were involved.
Ans.
```sql
SQL> select * from car;

REGNO                MODEL                                YEAR
-------------------- ------------------------------ ----------
ABCD0001             Celtos                                  3
EFGH2001             Ferrari                                32
DSDS0001             Urus                                    5
ABCD4001             Honda City                              1
HFSP5601             mini cooper                             7

SQL> select count(distinct driver_id#) from car natural join participated where model like 'Urus';

COUNT(DISTINCTDRIVER_ID#)
-------------------------
                        1
```

### Q3. Produce a listing with header as OWNER_NAME, No. of Accidents, and Total Damage Amount in a descending order on total damage.
Ans.
```sql
SQL> select name as OWNER_NAME,count(distinct DRIVER_ID#),sum(Damage_amount) as total_Damage from person natural join participated group by(name) order by(TOTAL_DAMAGE) DESC;

OWNER_NAME COUNT(DISTINCTDRIVER_ID#) TOTAL_DAMAGE
---------- ------------------------- ------------
Amogh                              1        26500
Rohan                              1        10000
Ramesh                             1          150
```

### Q4. List the Owners who made more than 2 accidents in a year.
Ans.
```sql
SQL> insert into participated  values(1236,'DSDS0001',99,100000000);

1 row created.

SQL> select name,extract(year from accd_date) as year,count(report_number) as total_accidents from person natural join participated join accident using (report_number) group by(name,extract(year from accd_date)) having count(report_number)>=2;

NAME             YEAR TOTAL_ACCIDENTS
---------- ---------- ---------------
Ramesh           2024               2
```

### Q5. List the owners who are not involved in any accident.
Ans.
```sql
SQL> select name from person where(driver_id#) not in(select driver_id# from participated);

NAME
----------
Rohit
Saarthak
```