linq - Defining a one-to-one relationship in SQL Server

Question

I need to define a one-to-one relationship, and can't seem to find the proper way of doing it in SQL Server.

Why a one-to-one relationship you ask?

I am using WCF as a DAL (Linq) and I have a table containing a BLOB column. The BLOB hardly ever changes and it would be a waste of bandwidth to transfer it across every time a query is made.

I had a look at this solution, and though it seems like a great idea, I can just see Linq having a little hissy fit when trying to implement this approach.

Any ideas?

Answer 1

One-to-one is actually frequently used in super-type/subtype relationship. In the child table, the primary key also serves as the foreign key to the parent table. Here is an example:

CREATE TABLE Organization
( 
     ID       int PRIMARY KEY,
     Name     varchar(200),
     Address  varchar(200),
     Phone    varchar(12)
)
GO

CREATE TABLE Customer
( 
     ID              int PRIMARY KEY,
     AccountManager  varchar(100)
)
GO

ALTER TABLE Customer
    ADD  FOREIGN KEY (ID) REFERENCES Organization(ID)
        ON DELETE CASCADE
        ON UPDATE CASCADE
GO