What is the proper way to define an oracle table who has an optional foreign key relationship with another table? For instance, some employee records have defined the country they are from (a FK from countries table), and some have not.
Share
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
What is the proper way to define an oracle table who has an optional foreign key relationship with another table? For instance, some employee records have defined the country they are from (a FK from countries table), and some have not.
Just allow the column to be nullable (don’t make it
NOT NULL) and create your foreign key as normal. The database will enforce the foreign key for any rows that contain a value in that row, but nothing will be enforced if the row is null.