SQL View Update

I am working on one application which uses the below query and updates a column in dcEQUI table with a number (0,1,2,3 etc ).

SELECT WebEQTYPList.[Description] FROM dbo.dcEQUI

LEFT OUTER JOIN dbo.WebEQTYPList
ON dbo.dcEQUI.EQTYP = dbo.WebEQTYPList.EQTYP
WHERE(dbo.WebEQTYPList.EQTYP IS NULL) -- I would like to understand that how it is updating dcEQUI table when no key column from dcEQUI table is used in this view. This view is executing on OnValidate event of a page built on ASPNET .

Everytime when a record on the page is validated same view is being used to update the column at the backend dcEQUI table.