I am trying to create a contact database of contacts at various companies. Contact persons and businesses are going to be stored in two separate tables in the database. I want each contact to be connected to a specific company. Am I supposed to use Foreign Key for all columns in the entire table or how is it made?
Contact table has following attributes:
This is too long for a comment. To address your comments on how the FK should look, this is the table structure you should be looking for:
Create Table Contact ( Id Int Identity(1,1) Not Null Primary Key Clustered, Firstname Varchar (20), Lastname Varchar (20), Email Varchar (50), Phone Varchar (15), CompanyId Int Not Null ) Create Table Company ( Id Int Identity(1,1) Not Null Primary Key Clustered, Name Varchar (100) ) Alter Table Contact Add Constraint FK_Contact_Company Foreign Key (CompanyId) References Company (Id)
You need to add an
Identity column to your tables to act as their
Next, you need to add a
CompanyId column to your
Contact table to hold the relationship.
And finally, you need to create the actual
Foreign Key Constraint.
Your datatypes are surely different from what I've guessed at, but this is the concept you should be using for your Foreign Key relationships.