text: 
  CREATE TABLE Cities (
    CityID INT NOT NULL,
    [Name] NVARCHAR(50) NOT NULL
  
    CONSTRAINT PK_Cities
    PRIMARY KEY(CityID)
  )
  
  CREATE TABLE Customers (
    CustomerID INT NOT NULL,
    [Name] NVARCHAR(50) NOT NULL,
    Birthday DATE ,
    CityID INT  NULL,
  
    CONSTRAINT PK_Customers
    PRIMARY KEY(CustomerID),
  
    CONSTRAINT FK_Customers_Cities
    FOREIGN KEY(CityID) REFERENCES Cities(CityID)
  
  )
  
  CREATE TABLE ItemTypes(
    ItemTypeID INT NOT NULL,
    [Name] NVARCHAR NOT NULL,
  
    CONSTRAINT PK_ItemTypes
    PRIMARY KEY(ItemTypeID)
  )
  
  CREATE TABLE Items(
    ItemID INT NOT NULL,
    [Name] NVARCHAR(50) NOT NULL,
    ItemTypeID INT NOT NULL,
  
    CONSTRAINT PK_Items
    PRIMARY KEY(ItemID),
  
    CONSTRAINT FK_Items_ItemsType
    FOREIGN KEY(ItemTypeID) REFERENCES ItemTypes(ItemTypeID)
  
  )
  
  CREATE TABLE Orders (
     OrderID INT IDENTITY NOT NULL,
     CustomerID INT NOT NULL,
  
     CONSTRAINT PK_Orders
     PRIMARY KEY(OrderID),
  
     CONSTRAINT FK_Orders_Customers
    FOREIGN KEY(CustomerID) REFERENCES Customers(CustomerID)
  )
  
  
  
  
  CREATE TABLE OrderItems(
     OrderID INT NOT NULL,
     ItemID INT NOT NULL
  
     CONSTRAINT PK_OrderItems
     PRIMARY KEY(OrderID , ItemID),
  
     CONSTRAINT FK_OrdersItems_Orders
     FOREIGN KEY(OrderID) REFERENCES Orders(OrderID),
  
     CONSTRAINT FK_OrdersItems_Items
     FOREIGN KEY(ItemID) REFERENCES Items(ItemID)
  )
  
  