Homework Database MySQL

CREATE TABLE Customers
(CustomerID int AUTO_INCREMENT,
CompanyName varchar(100),
ContactName varchar(100),
ContactTitle varchar(100),
Adress varchar(400),
City varchar(30),
Region varchar(30),
PostalCode smallint,
Country varchar(30),
Phone smallint,
Fax smallint,
CONSTRAINT c_Customers_PK PRIMARY KEY(CustomerID));

CREATE TABLE Orders
(OrderID int AUTO_INCREMENT,
CustomerID int,
EmployeeID int,
OrderDate date,
RequiredDate date,
ShipDate date,
ShipName varchar(50),
ShipAdress varchar(100),
ShipCity varchar(39),
ShipRegion varchar(39),
ShipCountry varchar(20));
alter table Orders add CONSTRAINT c_Orders_PK PRIMARY KEY(OrderID),
alter table Orders add CONSTRAINT c_Orders_FK FOREIGN KEY(CustomerID) REFERENCES Customers(CustomerID);
alter table Orders add CONSTRAINT c_Orders_FK_EmployeeID FOREIGN KEY(EmployeeID) REFERENCES employees(EmployeeID);

CREATE TABLE Products
(ProductID int AUTO_INCREMENT,
ProductName varchar(50),
SupplierID int,
CategoryID int,
UnitPrice double,
CONSTRAINT c_Products_PK PRIMARY KEY(ProductID));

alter table Products add CONSTRAINT c_Products_CategoryID FOREIGN KEY(CategoryID) REFERENCES Categories(CategoryID);
alter table Products add CONSTRAINT c_Products_SupplierID FOREIGN KEY(SupplierID) REFERENCES Suppliers(SupplierID);

create table Order_Details
(OrderID int,
ProductID int,
UnitPrice float,
Quantity smallint,
Discount decimal);
alter table Order_Details add CONSTRAINT c_Order_Details_Orders_FK FOREIGN KEY(OrderID, ProdcutID) REFERENCES Orders(OrderID)
alter table Order_Details add CONSTRAINT c_Order_Product_FK FOREIGN KEY(ProductID) REFERENCES Products(ProductID);

create table Categories
(CategoryID int AUTO_INCREMENT,
CategoryName varchar(50),
Description varchar(250),
CONSTRAINT c_Categories_PK PRIMARY KEY(CategoryID));

create table Employees
(EmployeeID int AUTO_INCREMENT,
LastName varchar(30),
FirstName varchar(30),
Title varchar(30),
TitleOfCourtsey varchar(30),
BirthDate date,
HireDate date,
Adress text,
City varchar(41),
Region varchar(41),
PostalCode smallint,
Country varchar(30),
HomePhone smallint,
ReportsTo int,
Salary decimal,
CONSTRAINT c_Employees_PK PRIMARY KEY (EmployeeID));
alert table employees add CONSTRAINT c_Report_To_FK FOREIGN KEY(ReportsTo) REFERENCES employees(EmployeeID);