create table foreign key

CREATE TABLE Sales.TempSalesReason 
   (
      TempID int NOT NULL, Name nvarchar(50)
      , CONSTRAINT PK_TempSales PRIMARY KEY NONCLUSTERED (TempID)
      , CONSTRAINT FK_TempSales_SalesReason FOREIGN KEY (TempID)
        REFERENCES Sales.SalesReason (SalesReasonID)
        ON DELETE CASCADE
        ON UPDATE CASCADE
   )
;

CREATE TABLE Orders
(

   
OrderID int NOT NULL,

   
OrderNumber int NOT NULL,

   
PersonID int,

   
PRIMARY KEY (OrderID),

   
FOREIGN KEY (PersonID) REFERENCES Persons(PersonID)

); 

ALTER TABLE Orders

ADD FOREIGN KEY (PersonID)
REFERENCES Persons(PersonID);