What is the full name of the customer who purchased the highest amount of total price in a single purchase?
full name of the customer = FirstName, MiddleInitial, LastName; highest amount of total price refers to MAX(MULTIPLY(Quantity, Price));
SELECT T2.FirstName, T2.MiddleInitial, T2.LastName FROM Sales AS T1 INNER JOIN Customers AS T2 ON T1.CustomerID = T2.CustomerID INNER JOIN Products AS T3 ON T1.ProductID = T3.ProductID GROUP BY T1.SalesID, T1.Quantity, T3.Price, FirstName, MiddleInitial, LastName ORDER BY T1.Quantity * T3.Price DESC LIMIT 1
CREATE TABLE Customers
(
    CustomerID    INTEGER         not null
        primary key,
    FirstName     TEXT not null,
    MiddleInitial TEXT null,
    LastName      TEXT not null
);
CREATE TABLE Employees
(
    EmployeeID    INTEGER         not null
        primary key,
    FirstName     TEXT not null,
    MiddleInitial TEXT null,
    LastName      TEXT not null
);
CREATE TABLE Products
(
    ProductID INTEGER            not null
        primary key,
    Name      TEXT    not null,
    Price     REAL null
);
CREATE TABLE Sales
(
    SalesID       INTEGER not null
        primary key,
    SalesPersonID INTEGER not null,
    CustomerID    INTEGER not null,
    ProductID     INTEGER not null,
    Quantity      INTEGER not null,
    foreign key (SalesPersonID) references Employees (EmployeeID)
            on update cascade on delete cascade,
        foreign key (CustomerID) references Customers (CustomerID)
            on update cascade on delete cascade,
        foreign key (ProductID) references Products (ProductID)
            on update cascade on delete cascade
);
