NULL when there's no relation.

Here's some sample data:

IF OBJECT_ID('tempdb..#Person','U') IS NOT NULL

BEGIN

DROP TABLE #Person

DROP TABLE #Job

DROP TABLE #PersonalJobs

END

CREATE TABLE #Person(

id INT PRIMARY KEY,

name NVARCHAR(50)

)

CREATE TABLE #Job(

id INT,

descr NVARCHAR(50)

)

CREATE TABLE #PersonJobs(

idP INT,

idJ INT,

startDate SMALLDATETIME

)

INSERT INTO #Person

SELECT 1,'PersonA'

UNION ALL

SELECT 2,'PersonB'

UNION ALL

SELECT 3,'PersonC'

INSERT INTO #Job

SELECT 1,'Builder'

UNION ALL

SELECT 2,'Painter'

UNION ALL

SELECT 3,'Destroyer'

INSERT INTO #PersonJobs

SELECT 1,1,GETDATE()

I created a row for PersonJobs, but in the first run it will be empty.

Thanks