joining two tables with nullable foreign key?

Question

I created two tables below, and FK_TypeID is nullable in this case. I want to write a query returning me the join of two tables.

if FK_TypeID is NULL for a certain row, the TypeName is also NULL. I am not sure how to go about creating such join statement?

[Actions]
ActionsID
Date
Message
FK_TypeID //links to the table below

[Type]
TypeID
TypeName

My current statment looks like this and it simply skips NULL FK_TypeID rows

SELECT        *
FROM            Actions 
INNER JOIN      TypeName ON Actions.FK_TypeID = [Type].TypeID

Help would be greatly appreciated!

Answer 1

You just need to use a LEFT JOIN

SELECT Actions.Date, Actions.Message, Type.TypeName
FROM Actions
    LEFT JOIN Type 
        ON Type.TypeID = Actions.FK_TypeID

If a match to Actions is not found to tie it with Type, then all columns in Type will be NULL.

Here is a good graphical visualization of the different types of joins in SQL

Answer 2

Use an OUTER JOIN

SELECT Actions.Date, Actions.Message, Type.TypeName 
FROM   Actions LEFT OUTER JOIN 
           Type ON Type.TypeID = Actions.FK_TypeID