I am in a situation where I need to query a database for data, but am struggling on how to properly form the query. Essentially I need to get data from the following tables:
Table: Contact contact_id INT [Primary Key] first_name VARCHAR(50) last_name VARCHAR(50) Table: Contact_Phone contact_id INT [Foreign Key/Composite Primary Key] phone_number VARCHAR(15) [Composite Primary Key] extension VARCHAR(10), NULL Table: Contact_Fax contact_id INT [Foreign Key/Composite Primary Key] fax_number VARCHAR(15) [Composite Primary Key] Table: Contact_Email contact_id INT [Foreign Key/Composite Primary Key] email VARCHAR(100) [Composite Primary Key]
Now not every single contact in my
Contacts table has a Phone, Fax, or Email. Some just have a phone or fax. Others just an email. There is one contact I know only has a phone number.
Now my issue is, if I try and make a simple query joining all of these tables look for specific contact information, if for any one of them there is no entry (for example, my one contact which doesn't have a fax or email) then I get no data being returned at all.
So the question is, how do I put this query together so that if I am trying to look up a specific contact's information, I will still be able to see all of the data (Phone/Fax/Email) even if one of them happens to be blank?