It is a bit late but I want to add some more details.
Actually it should be "Wittingen (Knesebeck)" or even better the "local district" (german "Ortsteil") which is in this case "Knesebeck" should be placed in a separate column as in the official source below does (the "Ortszusatz" can be ignored...it is in Germany the federal state already part of the geonames dataset):
https://www.postdirekt.de/plzserver/
Code:
PLZ Ortsname Ortszusatz Ortsteil
============================================
29379 Wittingen Niedersachs Hagen
29379 Wittingen Niedersachs Knesebeck
29379 Wittingen Niedersachs Mahnburg
29379 Wittingen Niedersachs Transvaal
29379 Wittingen Niedersachs Vorhop
29379 Wittingen Niedersachs Wunderbüttel
============================================
The problem currently is that the "local district" / "Ortsteil" is not stored in a separate column in the postal code data available for download and you have no way to separate this as it is simply added with a space to the locations name. More "common" is "Wittingen (Knesebeck)" or "Wittingen (OT: Knesebeck"...if you add the name of the local district at all.
Here another example from Germany...this is taken from the geonames postal code data I have imported into PostgreSQL. You can again compare it with the official source of postal codes (https://www.postdirekt.de/plzserver/).
The first row would be sufficient I think the rest is more detailed but as before it would be better to move the "local district" / "Ortsteil" to an extra column and maybe mark the hierarchical level and not just put the "local district" (german "Ortsteil") name after the location name just by separating it with a space.
Code:
postal_code location_name
========================
26736 Krummhörn
26736 Krummhörn Campen
26736 Krummhörn Canum
26736 Krummhörn Eilsum
26736 Krummhörn Freepsum
26736 Krummhörn Greetsiel
26736 Krummhörn Grimersum
26736 Krummhörn Groothusen
26736 Krummhörn Hamswehrum
26736 Krummhörn Jennelt
26736 Krummhörn Loquard
26736 Krummhörn Manslagt
26736 Krummhörn Pewsum
26736 Krummhörn Pilsum
26736 Krummhörn Rysum
26736 Krummhörn Upleward
26736 Krummhörn Uttum
26736 Krummhörn Visquard
26736 Krummhörn Woltzeten
26736 Krummhörn Woquard
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