topic Re: Geodatabase returns empty GeodatabaseFeatureTables collection in .NET Maps SDK Questions

Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Tue, 08 Aug 2017 17:29:04 GMT

I have come across a number of cases where the Geodatabase object has an empty collection of GeodatabaseFeatureTables. I have gone back and recreated everything from scratch, sometimes I have seen it fix the issues others not. When generating these replicas everything goes fine, I have checked Server logs and these only contain debug/info messages. Nothing indicative of errors. I can open the databases in DB Browser for SQLLite and everything looks fine.

After a bunch of research I have found one difference. The databases that work all seem to have a table called GDB_ServiceItems. The databases that show no layers none appear to have this table.

So a question, would this table missing cause the API to behave in this manner? Does the initialization of the Geodatabase object look to this table for information about the tables?

-Joe

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Sun, 12 Dec 2021 04:48:59 GMT

I just came here to post the same question. Hope we get some answers.

I've only tried one so far and it is coming up empty. It should have five layers. Also seems to have plenty of stuff.

I don't have a lot of Geodatabases to try. I'm hiring a person for ArcGIS desktop and asked them to follow the instructions here and here:

Create an offline layer—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

Creating ArcGIS Runtime content—Help | ArcGIS Desktop

The .geodatabase was created from data here. I'm happy to attach it if it helps:

http://services3.arcgis.com/IKBBLZOXy58PXgpl/ArcGIS/rest/services/Arizona_National_Scenic_Trail_Layers/FeatureServer

I'd like to know if the technician is doing something wrong or if I am programming something wrong.

I'll note that I have not found an exact example in 100.1 for opening a local geodatabase.

The code I have used is this. It crashes when it gets to the foreach loop because the list of feature tables is empty. There are no useful logs of any failure when opening it.

private async void Initialize()
         {
                   string filename = Android.OS.Environment.ExternalStorageDirectory.Path + Java.IO.File.Separator + "agisdata" + Java.IO.File.Separator + "featureserver.geodatabase";
 
             Geodatabase gdb = await Geodatabase.OpenAsync(filename);
             // Get all of the GeodatabaseFeatureTables from the geodatabase. They will be used to construct a FeatureLayer later.
 
 
             // Loop through each of the GeodatabaseFeatureTables and get its Name and ID to display that in a ListBox that user can then select and add to the Map as a FeatureLayer. 
             foreach (GeodatabaseFeatureTable oneFeatureTable in gdb.GeodatabaseFeatureTables)
             {
           
                 FeatureLayer myFeatureLayer = new FeatureLayer(oneFeatureTable
 
                 // Add the FeatureLayer to the Map.
                 myMap.OperationalLayers.Add(myFeatureLayer);
             }
 
 
 
             
 
 
         }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Thu, 10 Aug 2017 15:18:38 GMT

Something I tried which seems to be working. When doing the replica download I used the internal url of the service instead of the Web Adapter url. So instead of https://machine.domain.com/server/rest/services/MyService/FeatureServer. I used https://machine.domain.com:6443/arcgis/rest/services/MyService/FeatureServer. When I did this the replica was created correctly.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Thu, 10 Aug 2017 17:30:35 GMT

Do you mean when you are using GeoDatabaseSyncTask? Or is this something you do on ArcMap?

I see that might be helpful if I have any idea what the internal url of a service is. I have no idea for this one.

http://services3.arcgis.com/IKBBLZOXy58PXgpl/ArcGIS/rest/services/Arizona_National_Scenic_Trail_Layers/FeatureServer

I'm disappointed that ESRI hasn't weighed in on this. Either there are some undocumented steps that need to be done on the server or the desktop, some undocumented steps that must be done when opening the .geodatabase, or some undocumented bugs.

Being able to read from a local offline geodatabase is an absolute requirement and a big reason to use this runtime.

All the documentation seems to indicate this is possible, but so far I can not experience it.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Fri, 11 Aug 2017 18:43:35 GMT

I have experienced the same with the tables.

The sample geodatabases I've used successfully have the GDB_service items. The one I had created in ArcMap did not.

I found this screenshots which I believe is for the settings for the export. Are there other settings that may affect this?

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Fri, 11 Aug 2017 18:48:41 GMT

And in case, it matters, I am only looking for a read only view of the data in a .geodatabase file. I'm not interested in syncing it back anywhere. My level of licensing wouldn't allow that anyway.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Mon, 14 Aug 2017 20:19:24 GMT

I am doing everything with internal services and not using online esri services, so I have more control over how to access them. The solution I have does not seem possible using online esri services

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Tue, 15 Aug 2017 17:08:56 GMT

I don't see anything in the topics about runtime content that we are only allowed to use internal services.

I have the need to use data published by various government agencies.

I see this as a bug or inadequate documentation.

We tried it with the Optimize for View Only setting and the table was still missing.

Interestingly, the ItemInfo field appears to be the sort of thing that you can get from a query like this.

http://services3.arcgis.com/IKBBLZOXy58PXgpl/ArcGIS/rest/services/Arizona_National_Scenic_Trail_Layers/FeatureServer/0?f…

I found out she is using Arcmap 10.2.2 in case that makes a difference.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

AnttiKajanus1 — Tue, 15 Aug 2017 17:48:02 GMT

Hi guys,

I just noticed this topic and my take is that what is going on here is following: ArcMap is used to create a .geodatabase file through share as runtime content based on a Feature Service.

Fast googling indicates that ArcMap doesn't support generating .geodatabase files based on the feature services and they are only available through services pattern. I don't know if this limitation is in 10.2 but I would assume so (linked documentation is for 10.3)

Data from feature services and map services cannot be used. For more information on using services in ArcGIS Runtime SDKs, see Services pattern.

Creating ArcGIS Runtime content—Help | ArcGIS for Desktop

Did I get the issue correctly? Also, note that the used service doesn't actually support sync which is used to create the replica when using `GeodatabaseSyncTask`.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Tue, 15 Aug 2017 19:17:13 GMT

That is something I require clarification on.

Because after saying that, it then gives instructions for including feature layers. I admit I am not an ArcMap user, only want to hire one - so I guess there could be other types of Feature Layers.

And then it gives instructions for exporting tiles from a base map. How would it do that without using map services which it just said you couldn't use?

The sample geodatabases you provide seem to have come from a feature service.

And indeed, we are getting data this way, it is just leaving out a few details, some of the time, that stop it from actually working. There are full tables of data with shape data on each row.

I did try the GeodatabaseSyncTask with that service. It failed early on because the server doesn't support sync. I do not wish to make changes and sync with the server. I really only want to export but I don't see a way to tell it that. I don't think every Feature Server should have to allow anyone and everyone to sync data back to it in order to publish data that others can use.

But now you have opened up a new line of thinking.

When it links to "Services Pattern" I expected it to point to:

Create an offline layer—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

Which describes Geodatabase SyncTask.

But instead, it points to:

Create an offline map—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

Now I may have assumed that the GeodatabaseSync class was for vector layers while the OfflineMapTask was for tiled basemaps. Now not sure what to think.

It says:

At the 100.1 release the OfflineMapTask supports the following services:

Tiled image raster services that have the exportTiles capability enabled.
Feature services that have sync enabled.
Feature collections.

Again, it wants the feature services to have sync enabled, so this one may fail too. Excuse my ignorance - I don't know what Feature Collections means in this context. The FeatureCollection class in the runtime can be created from a set of Feature Services.

It has a Desktop pattern - I guess that you use ArcGIS Pro for this.

It creates an MMPK file, which for all I know, may contain a .geodatabase inside it.

Create an offline map—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

So what am I allowed to create a .geodatabase from? Shape files? File Geodatabases? Original works sketched in ArcGISMap?

Or do I even want to create a .geodatabase file? Maybe I want an mmpk file, especially if I don't want to sync back (and don't have a license to).

Nathan

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Tue, 15 Aug 2017 20:20:49 GMT

If your desire is to create offline content that is not edited I would look at either creating Runtime content on ArcMap or Mobile Map package in ArcGIS Pro. I am pretty certain you need a version above 10.3 to create Runtime Content in ArcMap. I would suggest using 10.4.1 or better.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

AnttiKajanus1 — Wed, 16 Aug 2017 13:23:00 GMT

Hi,

Hopefully this helps.

Taking layers offline using ArcGIS Runtime

- ExportTileCacheTask Class is used to generate a TPK file from a service that supports export operation

- GeodatabaseSyncTask Class is used to generate a geodatabase file from a service that has sync enabled

Taking a map offline using ArcGIS Runtime

- OfflineMapTask Class is used to generate a mobile map package based on a webmap which is using services that support operations mentioned above. Feature collections are set of features that are stored directly in webmaps or they live in a JSON format in an ArcGIS Portal item.

Creating layers for offline use with ArcMap

- ArcMap seems to work only with local content which means that if you create the geodatabase based on the feature service, it won't at the moment return any layers in it. The documentation indicates that this shouldn't work but I would assume that loading the geodatabase should fail instead it returning zero tables. I have raised a question to see if this is an area that we can do something. What comes to the TPK creation, the data also needs to be local (non-service based).

- If you want to use ArcMap to create the geodatabase, you first need to create a local copy from the data. This can be done by many different ways but one example is to use Feature Class To Geodatabase—Help | ArcGIS for Desktop tool.

- Note that it will copy only the data so you need to set the renderer / other needed information to the layers. You can, for example, create Layer Packages from the Feature Service layers and then apply them to the layers in your MXD by using Apply Symbology From Layer—Help | ArcGIS for Desktop

- If you create the geodatabase from the new map with full extent, it should work without problems.

Here is a picture from the linked service running in Runtime with a local geodatabase which was created with 10.5 ArcMap.

Please note that the service is in WGS84 projection so if you want to use our basemaps with the data, you need to project the local data first to the Web Mercator projection.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

AnttiKajanus1 — Wed, 16 Aug 2017 14:15:26 GMT

Btw, the datasets are really cool.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Wed, 16 Aug 2017 22:24:01 GMT

Antti Kajanus‌

Back to my original issue, I would be interested in knowing if the missing GDB_ServiceItems table would result in the behavior I see with the Geodatabase object containing no tables. The reason for the missing table would seem to be an issue for the server team, but I would be nice to have confirmation that the resultant behavior makes sense as a result of that table missing.

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

AnttiKajanus1 — Thu, 17 Aug 2017 08:19:37 GMT

Joe Hershman‌ yes, I highly believe so. I haven't seen situation yet where creating a replica will end up in a situation where it doesn't have the GDB_ServiceItems table in it. This is actually what happens when you try to create a geodatabase from ArcMap when the layers are pointing into a FeatureService and that is the reason why we don't get any tables out from the Geodatabase instance which seems to be loaded correctly.

If you can let me know more details so I can start pinging people about this. It's not very good if creating replica fails this manner every now and then and there is no way to know if the replica is corrupted or not.

Could you let me know following stuff (at least)
- Server version
- Server OS

- Runtime API version
- Server logs related to the generation

- Access to the service or way to generate the service

- Short summary of the use case

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

JoeHershman — Thu, 24 Aug 2017 17:50:42 GMT

Antti Kajanus‌ Just wanted to update you after doing some work with the replication team. It seems the issue is a result of us having the security access through WebAdpater not enabled in the our high availability architecture. Although this does not seem to be an issue in a single machine architecture. It still bugs me that it is a random thing and they don't really know why it happens, but early testing indicates this fix works.

Thanks

-Joe

Re: Geodatabase returns empty GeodatabaseFeatureTables collection

NathanMellor — Fri, 25 Aug 2017 15:15:55 GMT

What Antti looks like the information I need. I'll get these instructions to the contractor and try this again.

Since then, I've implemented something that uses MobileMapDownload. I've found that mmpk files can contain one or more .geodatabase files inside them.

I don't think it is realistic for me to expect many public feature servers to have sync enabled or allow all their layers to be taken offline.

So the desktop model is the way to go, and apparently under the right conditions an ArcGIS Pro user can get me an mmpk file and an ArcMap user can get me a .geodatabase file.