CREATE TABLE Customer ( 
    CustomerID MEDIUMINT AUTO_INCREMENT PRIMARY KEY, 
    First_Name VARCHAR(200) NOT NULL, 
    Last_Name VARCHAR(200) NOT NULL
    );



CREATE TABLE Invoice( 
    OrderID MEDIUMINT AUTO_INCREMENT PRIMARY KEY, 
    CustomerID INT UNSIGNED NOT NULL, 
    Date DATETIME NOT NULL, 
    TotalAmount DECIMAL(6,2) NOT NULL CHECK(TotalAmount > 0), 
    FOREIGN KEY(CustomerID) REFERENCES Customer(ID) ON DELETE CASCADE
    );


CREATE TABLE Payment ( 
    PaymentID MEDIUMINT UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
    OrderID INT UNSIGNED NOT NULL, 
    PaymentMethod VARCHAR(50) NULL,
    AmountPaid DECIMAL(6,2) NOT NULL CHECK(AmountPaid > 0), 
    PaymentDate DATETIME NOT NULL,
    FOREIGN KEY(OrderID) REFERENCES Invoice(OrderID) ON DELETE CASCADE
    );