Feature 403 SQLA 2 compatibility

[deniztepe]

Connectionless database queries are replaced with explicit connection initializations, since this functionality will be removed with the upcoming SQLAlchemy 2.0 version.

[nesnoj]

Thanks for the fix! If I remember correctly, I also had issues during CSV export. But I assume the review approvals included a (manual) test of this feature?

[chrwm]

I tested it for a few thousand units and all tables in #401 (the branch includes this PR already) and it worked fine. I'm running a full export now just to be sure.

[nesnoj]

I tested it for a few thousand units and all tables in #401 (the branch includes this PR already) and it worked fine. I'm running a full export now just to be sure.

Great, thx!

[chrwm]

When downloading a fresh dump from today, the export of all tables and all rows works fine. When trying to export an older sqlite db, this commit from 04.01.23 350dd1c leads to an error, as the new columns are not in the db.

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such column: gas_storage_extended.DatumDesBetreiberwechsels
[SQL: SELECT gas_storage_extended."DatenQuelle", gas_storage_extended."DatumDownload", gas_storage_extended."EinheitMastrNummer", gas_storage_extended."DatumLetzteAktualisierung", gas_storage_extended."LokationMastrNummer", gas_storage_extended."NetzbetreiberpruefungStatus", gas_storage_extended."NetzbetreiberpruefungDatum", gas_storage_extended."AnlagenbetreiberMastrNummer", gas_storage_extended."Land", gas_storage_extended."Bundesland", gas_storage_extended."Landkreis", gas_storage_extended."Gemeinde", gas_storage_extended."Gemeindeschluessel", gas_storage_extended."Postleitzahl", gas_storage_extended."Ort", gas_storage_extended."Strasse", gas_storage_extended."StrasseNichtGefunden", gas_storage_extended."Hausnummer", gas_storage_extended."Hausnummer_nv", gas_storage_extended."HausnummerNichtGefunden", gas_storage_extended."Laengengrad", gas_storage_extended."Breitengrad", gas_storage_extended."Registrierungsdatum", gas_storage_extended."Inbetriebnahmedatum", gas_storage_extended."EinheitSystemstatus", gas_storage_extended."EinheitBetriebsstatus", gas_storage_extended."NichtVorhandenInMigriertenEinheiten", gas_storage_extended."NameGasspeicher", gas_storage_extended."Speicherart", gas_storage_extended."MaximalNutzbaresArbeitsgasvolumen", gas_storage_extended."MaximaleEinspeicherleistung", gas_storage_extended."MaximaleAusspeicherleistung", gas_storage_extended."DurchschnittlicherBrennwert", gas_storage_extended."Weic", gas_storage_extended."Weic_Na", gas_storage_extended."SpeicherMastrNummer", gas_storage_extended."Gemarkung", gas_storage_extended."FlurFlurstuecknummern", gas_storage_extended."Adresszusatz", gas_storage_extended."DatumBeginnVoruebergehendeStilllegung", gas_storage_extended."DatumDesBetreiberwechsels", gas_storage_extended."DatumRegistrierungDesBetreiberwechsels" 
FROM gas_storage_extended]
(Background on this error at: http://sqlalche.me/e/14/e3q8)