Question

I have a table (TableA) where the primary key exists as a foreign key on another table (TableB). I am trying to write a SQL query (I am using SQL Server 2005) that will find all of the records in TableA where the primary key does not exist in TableB as a foreign key (we’ll say joining on TableAID). I suspect it will use an outer join, but I have been struggling. Can anyone help a SQL newb out?

Answer 1

SELECT A.*
FROM TableA AS A
LEFT JOIN TableB AS B ON (A.ID = B.TableAID)
WHERE B.TableAID IS NULL