[Qgis-user] Database options

Sat Oct 1 07:34:37 PDT 2016

Alex;
I was under the impression that the qgisRelationReferenceWidget and the
qgisRelationEditorWidget could handle m:n relationships. From what you are
saying I am not looking at building them in a Form using qt I am looking at
building a complete python plugin to handle those m:n relationships; Do you
know of any plugins that do this so I can look at how they were put
together? Online reference manuals/tutorials?
I have been searching this quite a bit over the last few months, founds
lots dealing with 1:m relationships but only short discussions on m:n
relationships and handling them. I do have an idea as to what I am doing; I
can get this sort of thing working in other packages. My specific troubles
are getting similar functionality working in QGIS.
Tyler

On Fri, Sep 30, 2016 at 4:06 PM, Alex M <tech_dev at wildintellect.com> wrote:

> You have to implement m:n relationships yourself inside of your plugin
> if you need that. I recommend trying to use an ORM like sql-alchemy to
> make life easier.
>
> FYI there's also some cool Offline plugins that let you take Postgis
> tables offline in a temporary spatialite db, and then sync when back
> online.
>
> Thanks,
> Alex
>
> On 09/30/2016 11:37 AM, Tyler Veinot wrote:
> > That was my thought for a solution, do the data entry in QGIS and use
> that
> > as the primary got to for entry and data retrieval using data entry forms
> > and widgets. Issue has been the m:n relationships. I downloaded
> postgreSQL
> > portable to try and since upgrading to 2.16.3 I have not tried my SQLite
> > forms to see if they work better as of yet; hoping to get to it this
> > weekend but I got quite a bit of work to do before I can get back to it.
> > Likely going to have to go with PostgreSQL; it is the only one that works
> > well with both platforms.
> > Tyler
> >
> > On Fri, Sep 30, 2016 at 2:27 PM, Alex M <tech_dev at wildintellect.com>
> wrote:
> >
> >> I looked for this unicorn many moons ago. It sadly doesn't exist. I have
> >> not found any interface quite like Access (which I have successfully
> >> used via ODBC to sqlite). Libre Base comes close but there's been many
> >> years of them saying they'd implement sqlite as a 1st class db and no
> >> movement, they always prefer Java based solutions it seems.
> >>
> >> The conclusion I reached is that you need either a web or local
> >> interface to your db. For data entry I looked into writing a custom
> >> Python application with the widgets I wanted for data entry, a node type
> >> app could work also (share code between a web interface and desktop
> >> interface). One option would be to make custom forms, or a plugin for
> >> QGIS and do all your data entry there.
> >>
> >> For writing queries there's lots of GUI tools, I usually use Spatialite
> >> GUI, QGIS QSpatialite Plugin, or Firefox SQLite Manager (non-spatial
> >> queries only). But both of these would be terrible for mass data entry.
> >>
> >> You could also, do a spreadsheet->csv->db script
> >>
> >> Thanks,
> >> Alex
> >>
> >> On 09/28/2016 11:06 AM, Tyler Veinot wrote:
> >>> Luigi;
> >>> Thanks, I will give it a try. Also tried using using MS Access to
> connect
> >>> to the SQLite database following steps I found online using an ODBC
> >>> connection. Got no useable sqlite3.dll found. It doesn't tell me where
> it
> >>> is looking or anything; the ODBC driver install did put an sqlite3.dll
> in
> >>> the system32 folder so I am not sure what the issue is, if the file is
> >> not
> >>> what access is looking for or if it is looking in the wrong spot for
> it;
> >>> Libre seems to be able to find it no problem.
> >>> Tyler
> >>>
> >>> On Wed, Sep 28, 2016 at 1:22 PM, Luigi Pirelli <luipir at gmail.com>
> wrote:
> >>>
> >>>> Tyler may you try with latest backported bugfixes on sqlite ogr
> >>>> provider? Probably related with your problem ("unable to commit
> >>>> changes to the database"). Check if it is similar following these
> >>>> steps: https://hub.qgis.org/issues/15351
> >>>>
> >>>> regards
> >>>> Luigi Pirelli
> >>>>
> >>>> ************************************************************
> >>>> **************************************
> >>>> * Boundless QGIS Support/Development: lpirelli AT boundlessgeo DOT com
> >>>> * LinkedIn: https://www.linkedin.com/in/luigipirelli
> >>>> * Stackexchange: http://gis.stackexchange.com/
> users/19667/luigi-pirelli
> >>>> * GitHub: https://github.com/luipir
> >>>> * Mastering QGIS:
> >>>> https://www.packtpub.com/application-development/mastering-qgis
> >>>> ************************************************************
> >>>> **************************************
> >>>>
> >>>>
> >>>> On 28 September 2016 at 17:54, Tyler Veinot <tylerkveinot at gmail.com>
> >>>> wrote:
> >>>>> I would prefer to go with postgre but I think that is going to have
> to
> >>>> be a
> >>>>> future project; right now we use a file geodatabase because it can be
> >>>> copied
> >>>>> and distributed. Some of our PC's are disconnected from a network
> >> and/or
> >>>>> have very limited network access. To my knowledge I cannot just copy
> a
> >>>>> Postgres, MySQL, Maria, or other like databases to a PC or tablet and
> >> run
> >>>>> them. I have run Postgre as a local service doing some testing and
> >>>> playing
> >>>>> but I have no place to put it for everyone to access, thats why I am
> >>>> looking
> >>>>> for a SQLite/File geodatabase type solution.
> >>>>> SQLite's only issue is that the qgsEditRelationWidget and
> >>>> qgsRelationWidget
> >>>>> don't seem to respond well to it. I have tried a number of different
> >>>> ways to
> >>>>> make those features work and it always ends in either a crash with
> >>>> minidump
> >>>>> or "unable to commit changes to the database". LibreBase does not
> >>>>> acknowledge SQLite's capabilities as a database; tried it with both
> >> JDBC
> >>>> and
> >>>>> ODBC drivers. I can build but cannot edit tables, will not support
> >>>> relations
> >>>>> or SQL Queries containing inner, outer, or full joins.
> >>>>> What about a GUI for SQLite? Something like Access for SQLite
> >> databases?
> >>>> If
> >>>>> there was such a thing I could move the data entry to that; looks
> like
> >> I
> >>>>> have some googling to do.
> >>>>> Tyler
> >>>>>
> >>>>> On Wed, Sep 28, 2016 at 12:01 PM, John Harrop <jcharrop at gmail.com>
> >>>> wrote:
> >>>>>>
> >>>>>> You could run it as a local server and it is available on all major
> >>>>>> platforms.  If you need a server with wider access you could look at
> >> AWS
> >>>>>> (even the free tier will give you some RDB service).  The Postgresql
> >>>>>> supported there has the PostGIS extension ready to load so for us it
> >>>> was a
> >>>>>> logical choice for hosting spatial data.
> >>>>>>
> >>>>>> John Harrop
> >>>>>> jcharrop at gmail.com
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>> On Sep 27, 2016, at 8:09 AM, Tyler Veinot <tylerkveinot at gmail.com>
> >>>>>>> wrote:
> >>>>>>>
> >>>>>>> Hello;
> >>>>>>> I need some database options; I tried PostgreSQL, HSQL,
> >>>>>>> SQLite/Spatialitem, Access (mdb/accdb) and what I get is either it
> >>>> works
> >>>>>>> well with QGIS and doesn't work well at all with LibreBase or vice
> >>>> versa,
> >>>>>>> with the exception of PostgeSQL which works well with both but I
> >>>> don't have
> >>>>>>> a server to run it on. Are there any other databases that you can
> >>>> suggest?
> >>>>>>> With no server at the moment I would like something that exists in
> a
> >>>> file in
> >>>>>>> the same way; SQLite, Access, or file geodatabases do, but also
> >>>> compatible
> >>>>>>> with QGIS and LibreBase.
> >>>>>>> Thanks;
> >>>>>>> Tyler
> >>>>>>> _______________________________________________
> >>>>>>> Qgis-user mailing list
> >>>>>>> Qgis-user at lists.osgeo.org
> >>>>>>> List info: http://lists.osgeo.org/mailman/listinfo/qgis-user
> >>>>>>> Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
> >>
> >>
> >
> >
> >
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