Name the sales person who helped Elizabeth A. White to purchase Road-250 Black, 48.
name of the sales person = FirstName, MiddleInitial, LastName; 'Road-250 Black, 48' is name of product;
SELECT DISTINCT T3.FirstName, T3.MiddleInitial, T3.LastName FROM Products AS T1 INNER JOIN Sales AS T2 ON T1.ProductID = T2.ProductID INNER JOIN Employees AS T3 ON T2.SalesPersonID = T3.EmployeeID INNER JOIN Customers AS T4 ON T2.CustomerID = T4.CustomerID WHERE T4.MiddleInitial = 'A' AND T4.LastName = 'White' AND T1.Name = 'Road-250 Black, 48' AND T4.FirstName = 'Elizabeth'
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
);
