Technically the Schengen Visa allows you to enter via any Schengen country.
Officially you are supposed to request a Schengen visa via either the country you intend to first enter the Schengen zone via (in this case, Germany) OR the country in which you intend to spend most of your time (Holland). However in general this rule is not strongly enforced unless the border officials at the country you are entering throught believe that you have specifically requested a visa via a country in order to bypass some form of checks/etc.
Keep in mind that when you fly into the Schengen Area, you pass through immigration in the country where you first land, and further flights after that are basically "domestic" flights. So even though you're saying that you intend to enter via Germany, if you end up flying Air France (for example) you will almost certainly enter Schengen in France, and then catch a domestic flight to Germany, followed by another domestic flight to Holland at a later stage. ie, People enter via different countries than that their visa was issued by all the time, based simply on the airline that they are flying!