Missing Fields

I am a newbie to access and i'm going through various tutorials to pick up how access works.

The following are my two tables:

DB
Product
Item
Name
Source

DATA
Name
Volume
Time
Total

Within my DB I have A, B and C within the Name Fields but within my DATA table I have A, B, C and D. I have managed to write the following query to link the two tables:

SELECT DB.Product, DB.[Item], DB.[Name], Data.Volume, Data.Time, Data.Total
FROM DB LEFT JOIN Data ON DB.[Name]=Data.[Name];

but how do i get to add the missing name D into my DB table?

Please could somebody help. Thanks in advance.