SQL Server : code created and not sure why it is not processing - foreign key problem? - sql

Question

CREATE TABLE THREE_GIRLS_COFFEE_HUT
(
ShopName Char NOT NULL,
PhoneNumber Char(12) NOT NULL,
Address Char(20) NOT NULL,
City Char(20) NOT NULL,
State Char(2) NOT NULL,
ZipCode Char(5) NOT NULL,
CONSTRAINT ShopPK PRIMARY KEY (ShopName)
);
CREATE TABLE EMPLOYEE
(
EmployeeID Int NOT NULL IDENTITY(1,1),
EmployeeName Char(30) NOT NULL,
PhoneNumber Char(10) NOT NULL,
Address Char(20) NOT NULL,
City Char(20) NOT NULL,
State Char(2) NOT NULL,
ZipCode Char(5) NOT NULL,
EmployeeType Char(10) NOT NULL,
ShopName Char (25) FOREIGN KEY REFERENCES THREE_GIRLS_COFFEE_HUT (ShopName)
CONSTRAINT EmployeePK PRIMARY KEY(EmployeeID),
CONSTRAINT EmployeeAK1 UNIQUE(EmployeeName)
);
CREATE TABLE CUSTOMER
(
CustomerID Int NOT NULL IDENTITY(1000,1),
CustomerName Char(30) NULL,
PhoneNumber Char(10) NULL,
EmailAddress Char(30) NOT NULL,
CONSTRAINT CustomerPK PRIMARY KEY(CustomerID),
CONSTRAINT CustomerAK1 UNIQUE(EmailAddress)
);
CREATE TABLE [ORDER]
(
SalesOrderNumber INT NOT NULL IDENTITY (1500,1),
Date Numeric(6) NOT NULL,
Subtotal Numeric(6, 2) NOT NULL,
Tax Numeric(6, 2) NOT NULL,
Total Numeric(6, 2) NOT NULL,
CONSTRAINT OrderPK PRIMARY KEY (SalesOrderNumber),
CONSTRAINT EmpOrdFK FOREIGN KEY(EmployeeID)
REFERENCES EMPLOYEE(EmployeeID)
ON UPDATE CASCADE
ON DELETE NO ACTION,
CONSTRAINT CustOrdFK FOREIGN KEY (CustomerID)
REFERENCES CUSTOMER(CustomerID)
ON UPDATE NO ACTION
ON DELETE NO ACTION
);
CREATE TABLE PRODUCT
(
ProductNumber Int NOT NULL IDENTITY(2000,1),
ProductDescription Char(20) NOT NULL,
QuantityOnOrder Numeric(4) NOT NULL,
QuantityOnHand Numeric(4) NOT NULL,
OrderDate Date NOT NULL,
ExpirationDate Date NOT NULL,
CONSTRAINT ProductPK PRIMARY KEY(ProductNumber),
CONSTRAINT ValidExpDate CHECK (ExpirationDate > OrderDate)
);
CREATE TABLE MENU_ITEM (
ItemNumber Int NOT NULL IDENTITY(3000,1),
ItemDescription Char(30) NOT NULL,
ItemCost Numeric(6,2) NOT NULL,
ProductNumber Int FOREIGN KEY REFERENCES PRODUCT(ProductNumber)
CONSTRAINT MenuPK PRIMARY KEY(ItemNumber),
CONSTRAINT MenuAK1 UNIQUE(ItemDescription),
);
CREATE TABLE ORDER_LINE_ITEM (
SalesOrderNumber INT FOREIGN KEY REFERENCES [ORDER](SalesOrderNumber),
ItemNumber INT FOREIGN KEY REFERENCES MENU_ITEM(ItemNumber),
Quantity Numeric NOT NULL,
UnitPrice Numeric(6,2) NOT NULL,
ExtendedPrice Numeric (6,2) NOT NULL,
);
I got these errors and it will not process- I think I have problem with my foreign key but I am not sure.
Msg 1769, Level 16, State 1, Line 40
Foreign key 'EmpOrdFK' references invalid column 'EmployeeID' in referencing table 'ORDER'.
Msg 1750, Level 16, State 0, Line 40
Could not create constraint or index. See previous errors.

Answer 1

There's no column EmployeeID in the ORDER table, so:
EmpOrdFK FOREIGN KEY(EmployeeID) REFERENCES EMPLOYEE(EmployeeID)
which says, create a foreign key in which Order.EmployeeId references Employee.EmployeeId, can't work.
Did you want to add an EmployeeId column to Order?
(There's also no CustomerId in Order, so the next line
CONSTRAINT CustOrdFK FOREIGN KEY (CustomerID)
would have failed too, except it never got to run because of the first error.)
You probably want to add EmployeeId and CustomerId to the Order table.

Answer 2

When you are mapping foreign key from Order table to Employee table, you have to map on common column in both tables. If you look at order table, which is missing employeeId in
that table.
And also don't call it as ORDER table. ORDER is reserved keyword in SQL server.
References: https://learn.microsoft.com/en-us/sql/t-sql/language-elements/reserved-keywords-transact-sql?view=sql-server-ver15