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## Week 7 - DBMS Lab - PL SQL & Triggers ## Week 7 - DBMS Lab - PL SQL & Triggers
### DB
```sql
SQL> select table_name from user_tables;
TABLE_NAME
--------------------------------------------------------------------------------
ACCIDENT
CAR
OWNS
PARTICIPATED
PERSON
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
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 * from owns;
DRIVER_ID# REGNO
------------------------------ --------------------
1234 ABCD0001
1235 EFGH2001
1236 DSDS0001
1237 ABCD4001
1238 HFSP5601
SQL> select * from participated;
DRIVER_ID# REGNO REPORT_NUMBER DAMAGE_AMOUNT
------------------------------ -------------------- ------------- -------------
1234 ABCD0001 1 10000
1236 DSDS0001 3 150
1238 HFSP5601 5 1500
1238 HFSP5601 12 25000
SQL> select * from person;
DRIV NAME ADDRESS
---- ---------- ------------------------------
1234 Rohan Delhi India
1237 Saarthak Manipal India
1236 Ramesh Maharashtra India
1235 Rohit Banglalore India
1238 Amogh Muzaffarnagar
```
### Q1. Generate a trigger displaying driver information, on participating in an accident.
Trigger:
```sql
CREATE OR REPLACE TRIGGER trg_display_driver_info
AFTER INSERT ON participated
FOR EACH ROW
DECLARE
v_driver_name VARCHAR2(100);
v_driver_address VARCHAR2(255);
BEGIN
-- Fetch driver information based on DRIVER_ID#
SELECT NAME, ADDRESS
INTO v_driver_name, v_driver_address
FROM person
WHERE DRIVER_ID# = :NEW.DRIVER_ID#;
-- Display the driver information
DBMS_OUTPUT.PUT_LINE('Driver ID: ' || :NEW.DRIVER_ID#);
DBMS_OUTPUT.PUT_LINE('Driver Name: ' || v_driver_name);
DBMS_OUTPUT.PUT_LINE('Driver Address: ' || v_driver_address);
DBMS_OUTPUT.PUT_LINE('Car Registration Number: ' || :NEW.REGNO);
DBMS_OUTPUT.PUT_LINE('Report Number: ' || :NEW.REPORT_NUMBER);
DBMS_OUTPUT.PUT_LINE('Damage Amount: ' || :NEW.DAMAGE_AMOUNT);
END;
/
```
Demo:
```sql
SQL> INSERT INTO participated (DRIVER_ID#, REGNO, REPORT_NUMBER, DAMAGE_AMOUNT)
2 VALUES (1235, 'EFGH2001', 3, 5000);
Driver ID: 1235
Driver Name: Rohit
Driver Address: Banglalore India
Car Registration Number: EFGH2001
Report Number: 3
Damage Amount: 5000
Driver_id: 1235 Name: Rohit Address: Banglalore India
1 row created.
```
### Q2.
### Q3. List cars involved in accidents with cumulative damage exceeding a specific amount.
Checking for damage amount > 10000, we have
```SQL
SQL> SELECT
p.driver_id#,
o.regno,
SUM(pa.damage_amount) AS total_damage
FROM
PARTICIPATED pa
JOIN
OWNS o ON pa.driver_id# = o.driver_id#
JOIN
PERSON p ON o.driver_id# = p.driver_id#
GROUP BY
p.driver_id#, o.regno
HAVING
SUM(pa.damage_amount) > 10000;
DRIVER_ID# REGNO TOTAL_DAMAGE
------------------------------ -------------------- ------------
1238 HFSP5601 26500
```
### Q4. Identify cars that have been involved in more than one accident and calculate the total damage for each car.
```SQL
SQL> SELECT
o.regno,
COUNT(DISTINCT pa.report_number) AS accident_count,
SUM(pa.damage_amount) AS total_damage
FROM
PARTICIPATED pa
JOIN
OWNS o ON pa.driver_id# = o.driver_id#
GROUP BY
o.regno
HAVING
COUNT(DISTINCT pa.report_number) > 1;
REGNO ACCIDENT_COUNT TOTAL_DAMAGE
-------------------- -------------- ------------
HFSP5601 2 26500
```
### Q5. Calculate the average damage amount for accidents at each location.
```sql
SQL> SELECT
a.location,
AVG(pa.damage_amount) AS average_damage
FROM
ACCIDENT a
JOIN
PARTICIPATED pa ON a.report_number = pa.report_number
GROUP BY
a.location;
LOCATION AVERAGE_DAMAGE
-------------------------------------------------- --------------
karnataka India 25000
Delhi India 10000
India 2575
Gujrat India 1500
```