I am looking for a French verb which conveys the meaning of the German word 'pflegen'. In particular in the IT sense of maintaining data (Datenpflegen) by keeping data up-to-date and consistent. I'm also looking for related words such as 'Daten einpflegen' (Data entry).
As a native German, here are my thoughts:
I'm not sure if any French word does have a similar figurative meaning as einpflegen does have, but the suggested word maintenir sounds quite OK to me. Especially because there are a lot of results on Google for maintenir and données in context with SQL and SAP.
Comparing back-translations to German instand halten, aufrechterhalten and such are also expressing what you want to say. Additionally, Pons translates Pflege and Wartung with entretien et maintenance and Programmwartung with maintenance du programme.
As comments point out, entretien doesn't actually fit in context of data. It is more appropriate when talking about maintaining roads or such. The English maintenance is AFAIK also more about maintaining machines, roads etc., not software or data. However, I consider maintenance as barely suitable for Datenpflege.
Hence another, perhaps better, possibility might be mise à jour des données. It simply means to update and this is the closest match I came across in my Google search.
Last but not least, a translation I'd consider as appropriate for einpflegen is saisir. It means to supply or to put in texts, values etc.
I'm no German speaker myself, but from what you have explained, I would translate Datenpflegen into Maintenir des données à jour.
As for Daten einpflegen, it could be translated to Entrée / Introduction de données, or Entrer / Introduire des données for the verbal form.
Edit: User Em1 came up with an even better translation for Daten einpflegen : Saisie de données / Saisir des données.
'La maintenance' grates horribly on my ears as Frenglish, but it is absolutely what French engineers call it. So 'maintenir les donnees' would be totally correct. But entretenir calls rags and polish to mind :-), or something you'd do to your car. Another vote for 'maintenir', in short.
I don't speak German at all but, by your English description, it seems that « synchronisation des données » could match the meaning.
If it can't fit in the label, you can use « synchro des données » or even « MAJ données ».