Geo support

[SebastianStehle]

No description provided.

[SebastianStehle]

I have not worked on sqlite yet, but it should look very similar. The problem is to install the binaries here.

[PhenX]

I seems like adding

<PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.11" />

To the Tests package makes it work also for Sqlite

[SebastianStehle]

I don't know what is wrong now. I am really lost. I can't find the damn error :(

[SebastianStehle]

Okay, I am done.

I have also simplified the test fixtures a little bit and fixed a bug in the metadata provider with multiple contexts. I still have not figured out how to make Sqlite workign locally and in github, but this is probably something for another PR.

[PhenX]

OK I'll review it tonight

[PhenX]

I'm not a big fan of the NetTopologySuite dependency, did you consider resolving a ITypeMappingSource? The one for Sql server for example https://github.com/dotnet/efcore/blob/main/src/EFCore.SqlServer/Storage/Internal/SqlServerTypeMappingSource.cs

[SebastianStehle]

I don#t get it. How would you make the conversion then?

The point is the following: Geo is provided by extensions in EF, which do the actual conversion. You have to basically the same to support the correct types. NetTopologySuite seems to be the defacto standard, so largish applications have the dependency anyway.

[PhenX]

Well EF knows how to convert geo types when we call UseNetTopologySuite, so I think we should use these converters

[SebastianStehle]

How?

[SebastianStehle]

For exmaple we already use this method to get the correct type for postgres:

        var mapping = column.Property.GetRelationalTypeMapping() as NpgsqlTypeMapping;

        return mapping?.NpgsqlDbType;

But for Geography we get no mapping at all.

[PhenX]

At least for NPGSQL, I'll have to check for others, but we can use the mapping to get the underlying NpgsqlDbType, which seems to be different for bulk insert (bytea, seeing your code)

here geo is an instance of Point which inherits Geometry

[PhenX]

Let me go further, I'm not sure I went deep enough in your PR

[SebastianStehle]

Sure, I basically went from error to error. Always got something like "Cannot convert from x to y"

[SebastianStehle]

e.g. SQL Server accepts geopoints in reverse coordination order (Y, X) not (X, Y)

[PhenX]

Ok, I thought I could find something among mapping sources, but no...

[SebastianStehle]

There are internal APIs, they are called ProviderConverter, but I could not find any way to get access to them.

[SebastianStehle]

A release would be awesome.