DatabaseManagementSystems/Practical/Practical Exam/PL-SQL/P2 - Unnamed PL-SQL.md

P2 - Unamed PL-SQL

Problem Statement: Write an Unnamed PL/SQL of code for the following requirements: - Schema: Borrower (Rollin, Name, DateofIssue, NameofBook, Status) Fine (Roll_no,Date,Amt) Accept roll_no & name of book from user. Check the number of days (from date of issue).

1. If days are between 15 to 30 then fine amounts will be Rs 5 per day.
2. If no. of days>30, per day fine will be Rs 50 per day & for days less than 30, Rs. 5 per day.
3. After submitting the book, status will change from I to R.
4. If condition of fine is true, then details will be stored into fine table.

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Creating tables

CREATE TABLE Borrower (
  rollin NUMBER,
  Name VARCHAR2(255),
  DateofIssue DATE,
  NameofBook VARCHAR2(255),
  Status VARCHAR(255),
  PRIMARY KEY (rollin)
);

CREATE TABLE Fine (
  Roll_no NUMBER,
  DateofReturn DATE,
  Amt NUMBER,
  FOREIGN KEY (Roll_no) REFERENCES Borrower (rollin)
);

Warning

Notice inconsistent naming for columns? We're just doing it by the books. Blame the one who made these problem statements.

Inserting data

INSERT INTO Borrower VALUES (1, 'Kalas', TO_DATE('2024-10-19', 'YYYY-MM-DD'), 'DBMS', 'I');
INSERT INTO Borrower VALUES (2, 'Himanshu', TO_DATE('2024-11-01', 'YYYY-MM-DD'), 'IOT', 'I');
INSERT INTO Borrower VALUES (3, 'Mepa', TO_DATE('2024-10-29', 'YYYY-MM-DD'), 'TOC', 'I');
INSERT INTO Borrower VALUES (4, 'Jambo', TO_DATE('2024-10-20', 'YYYY-MM-DD'), 'CNS', 'I');

Procedure

DECLARE
  p_roll NUMBER;
  p_book VARCHAR2(255);
  p_issueDate DATE;
  totalDays INT;
  fineAmt INT;
  nodata EXCEPTION;
BEGIN
  DBMS_OUTPUT.PUT_LINE('Enter roll number: ');
  p_roll := &p_roll; -- specify value directly for Live SQL. Eg.: p_roll := 1;
  DBMS_OUTPUT.PUT_LINE('Enter book name: ');
  p_book := &p_book; -- specify value directly for Live SQL. Eg.: p_roll := 'DBMS';

  IF (p_roll <= 0) THEN
    RAISE nodata;
  END IF;

  SELECT DateofIssue INTO p_issueDate FROM Borrower WHERE rollin = p_roll AND NameofBook = p_book;
  SELECT TRUNC(SYSDATE) - p_issueDate INTO totalDays FROM dual;

  IF (totalDays > 30) THEN
    fineAmt := (15 * 5) + ((totalDays - 15) * 50); -- Rs 5 for first 15 days, Rs 50 for remaining
    DBMS_OUTPUT.PUT_LINE('Roll no. ' || p_roll || ' has been fined Rs. ' || fineAmt);
    INSERT INTO Fine VALUES (p_roll, SYSDATE, fineAmt);
    UPDATE Borrower SET Status = 'R' WHERE Rollin = p_roll AND NameofBook = p_book;
  ELSIF (totalDays BETWEEN 15 AND 30) THEN
    fineAmt := totalDays * 5;
    DBMS_OUTPUT.PUT_LINE('Roll no. '|| p_roll || ' has been fined Rs. ' || fineAmt);
    INSERT INTO Fine VALUES (p_roll, SYSDATE, fineAmt);
    UPDATE Borrower SET Status = 'R' WHERE Rollin = p_roll AND NameofBook = p_book;
  ELSE
    fineAmt := 0;
    DBMS_OUTPUT.PUT_LINE('No fine for roll no. '|| p_roll);
    INSERT INTO Fine VALUES (p_roll, SYSDATE, fineAmt);
    UPDATE Borrower SET Status = 'R' WHERE Rollin = p_roll AND NameofBook = p_book;
  END IF;
EXCEPTION
  WHEN nodata THEN
    DBMS_OUTPUT.PUT_LINE('Please enter a valid roll number.');
  WHEN NO_DATA_FOUND THEN
    DBMS_OUTPUT.PUT_LINE('Something went wrong. Please check input data.');
  WHEN OTHERS THEN
    DBMS_OUTPUT.PUT_LINE('Error occured. Error: ' || SQLERRM);
END;
/

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