Database

I created a AWS RDS database and made two tables. One called User which contains UserID, LastName, FirstName, Mail and PrivilegedID, and the second one PrivilegeID and Privilege.

AWS RDS
  endpoint connection: database.cwghi2srchfe.eu-west-2.rds.amazonaws.com
  port: 3306
  user: admin
  password: administrator
  database name: database

commands used:
  CREATE TABLE `database`.`Users` (
  `UserID` INT NOT NULL,
  `LastName` VARCHAR(45) NULL,
  `FirstName` VARCHAR(45) NULL,
  `Mail` VARCHAR(255) NULL,
  `PrivilegeID` INT NULL,
  PRIMARY KEY (`UserID`));

CREATE TABLE `database`.`Privileges` (
  `PrivilegeID` INT NOT NULL,
  `Privilege` VARCHAR(45) NULL,
  PRIMARY KEY (`PrivilegeID`));
  
INSERT INTO Privileges VALUES (1, 'Admin');
INSERT INTO Privileges VALUES (0, 'User');

24.5.

I added three tables to this database, Bill, BillID and Product. Table Bill has bill_id, company_name, company_address, date, place, product_id, total_price and responsible_person.
Table BillID has only bill_id that I inner joined with bill_id from Bill.
Table Product has product_id, description and price. product_id is inner joined with product_id from Bill.
 

SELECT Bill.product_id FROM Bill
INNER JOIN Product ON Product.product_id=Bill.product_id;

SELECT Bill.bill_id FROM Bill
INNER JOIN BillID ON BillID.bill_id=Bill.bill_id;