DatabaseManagementSystems/Practical/Assignment-A2/Queries-A2.md

Database Queries for Assignment-A2

This file contains all the queries required to build the database

Creating database

CREATE DATABASE Database_A2;
USE Database_A2;

Creating tables and specify primary keys:

CREATE TABLE Account(accountNum INT, branchName VARCHAR(50), balance INT, PRIMARY KEY (accountNum));
CREATE TABLE Branch(branchName VARCHAR(50), branchCity VARCHAR(50), assets INT, PRIMARY KEY (branchName));
CREATE TABLE Customer (customerName VARCHAR(50), customerStreet VARCHAR(50), customerCity VARCHAR(50), PRIMARY KEY (customerName));
CREATE TABLE Depositor (customerName VARCHAR(50), accountNum INT);
CREATE TABLE Loan (loanNum INT, branchName VARCHAR(50), amount INT, PRIMARY KEY (loanNum));
CREATE TABLE Borrower (customerName VARCHAR(50), loanNum INT);

Altering tables to specify foreign keys

ALTER TABLE Account ADD FOREIGN KEY (branchName) REFERENCES Branch(branchName);
ALTER TABLE Depositor ADD FOREIGN KEY (customerName) REFERENCES Customer (customerName);
ALTER TABLE Depositor ADD FOREIGN KEY (accountNum) REFERENCES Account (accountNum);
ALTER TABLE Loan ADD FOREIGN KEY (branchName) REFERENCES Branch (branchName);
ALTER TABLE Borrower ADD FOREIGN KEY (customerName) REFERENCES Customer (customerName);
ALTER TABLE Borrower ADD FOREIGN KEY (loanNum) REFERENCES Loan (loanNum);

Adding data

INSERT INTO Branch (branchName, branchCity, assets) VALUES
("Dhole Patil", "Kharadi", 50000),
("Nagarwala", "Akurdi", 20000),
("Peachtree", "Wakad", 35000),
("Bishops", "Nigdi", 10000),
("Amanora", "Hadapsar", 60000);

INSERT INTO Customer (customerName, customerStreet, customerCity) VALUES
("Kalas", "Airport Road", "Pune"),
("Mehul", "Shahdha", "Nandurbar"),
("Tanmay", "Porwal Road", "Pune"),
("Kshitij", "Hadapasar", "Pune"),
("Aditya", "Mira RD", "Mumbai"),
("Himanshu", "Smart City", "Nandurbar");

INSERT INTO Account (accountNum, branchName, balance) VALUES
(2501, "Dhole Patil", 5000),
(2511, "Nagarwala", 1500),
(2521, "Peachtree", 2000),
(2512, "Bishops", 5000),
(2531, "Amanora", 1000);

INSERT INTO Loan (loanNum, branchName, amount) VALUES
(155, "Dhole Patil", 500),
(156, "Nagarwala", 250),
(157, "Peachtree", 600),
(158, "Bishops", 9000),
(159, "Amanora", 25000);

INSERT INTO Borrower VALUES
("Kalas", 156),
("Mehul", 158),
("Tanmay", 155),
("Kshitij", 157),
("Aditya", 159),
("Himanshu", 158);

INSERT INTO Depositor VALUES
("Kalas", 2511),
("Mehul", 2512),
("Tanmay", 2501),
("Kshitij", 2521),
("Aditya", 2531),
("Himanshu", 2512);

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Running queries

1. Find the names of all branches in loan relation.

SELECT branchName FROM Loan;

2. Find all loan numbers for loans made at Akurdi Branch with loan amount > 12000.

SELECT loanNum FROM Loan WHERE amount>12000;

3. Find all customers who have a loan from bank. Find their names,loan_no and loan amount.

SELECT * from Borrower;
SELECT Borrower.loanNum FROM Borrower INNER JOIN Loan ON Borrower.loanNum = Loan.loanNum;

==TESTING PENDING==

4. List all customers in alphabetical order who have loan from Akurdi branch.

SELECT customerName
FROM Borrower
WHERE loanNum IN (SELECT loanNum FROM Loan WHERE branchName = 'Akurdi')
ORDER BY customerName;

5. Find all customers who have an account or loan or both at bank.

SELECT DISTINCT customerName
FROM (SELECT customerName FROM Account UNION SELECT customerName FROM Borrower) AS Customers;

6. Find all customers who have both account and loan at bank.

SELECT customerName
FROM Account
WHERE customerName IN (SELECT customerName FROM Borrower);

7. Find all customers who have account but no loan at the bank.

SELECT customerName
FROM Account
WHERE customerName NOT IN (SELECT customerName FROM Borrower);

8. Find the average account balance at each branch

SELECT branchName, AVG(balance) AS avg_balance
FROM Account
GROUP BY branchName;

9. Find no. of depositors at each branch.

SELECT branchName, COUNT(DISTINCT customerName) AS num_depositors
FROM Account
GROUP BY branchName;

10. Find name of Customer and city where customer name starts with Letter P.

SELECT customerName, city
FROM Customer
WHERE customerName LIKE 'P%';

11. Display distinct cities of branch.

SELECT DISTINCT city
FROM Branch;

12. Find the branches where average account balance > 12000

SELECT branchName
FROM Account
GROUP BY branchName
HAVING AVG(balance) > 12000;

13. Find number of tuples in customer relation.

SELECT COUNT(*) AS num_tuples
FROM Customer;

14. Calculate total loan amount given by bank.

SELECT SUM(amount) AS total_loan_amount
FROM Loan;

15. Delete all loans with loan amount between 1300 and 1500.

DELETE FROM Loan
WHERE amount BETWEEN 1300 AND 1500;

16. Delete all tuples at every branch located in Nigdi.

DELETE FROM Account
WHERE branchName IN (SELECT branchName FROM Branch WHERE city = 'Nigdi');

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