I'm trying to add a key from my customer table to my reservation table in oracle.
However I keep getting an error message when I try to run my SQL commands which states 'Customer_ID is an invalid identifier'.
What I am trying to do is first use an alter statement to alter the reservation table.
Then I am adding a foreign key, which is called 'Customer_ID'
Then I enter a references statement, which tells it that I am getting the CUSTOMER_ID attribute from the customer table. However to sql this doesn't make sense at all.
To me, logically it makes sense, I don't see anything wrong with the syntax or structure of the statements. Any sharp eyes/minds to help me on this matter would be greatly appreciated.
the statements used are:
ALTER TABLE reservation
ADD FOREIGN KEY (Customer_ID)
REFERENCES Customer(Customer_ID);