Implement spatial data types

Implement support for spatial data types: GEOMETRY, POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION.

http://dev.mysql.com/doc/refman/5.7/en/spatial-datatypes.html

Required for #4.

[caleblloyd]

I’ve read through MySqlGeometry a few times, and it seems very unfinished. The GEOMETRY type is supposed to be able to hold POINT, LINESTRING, or POLYGON, but from reading the source, it appears to me that MySqlGeometry only supports inserting POINT.

I can’t find anything about MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, or GEOMETRYCOLLECTION in Connector/NET.

.NET Core has no System.Data.Spatial namespace as of yet. Other versions of .NET have System.Data.Spatial.DbGeography, and it is probably tailored to work with SQL Server, which supports all of MySQL’s spatial types and more.

EF Core has an open issue (https://github.com/aspnet/EntityFramework/issues/1100) to add Spatial support, which will likely come with DB-agnostic spatial abstractions. The most useful approach to programmers would likely be a library outside of this one that implements these forthcoming DB-agnostic spatial abstractions for MySQL.

I ran a query through BigQuery’s Sample GitHub Content representing 10% of public content on GitHub, searching for MySqlGeometry. Only 2 repos showed up, Connector/NET and another which looks like it no longer even uses it.

Randomly sampled 10% of text file contents from [bigquery-public-data:github_repos.contents].

    SELECT
      sample_repo_name
    FROM
      [bigquery-public-data:github_repos.sample_contents]
    WHERE
      NOT binary
      AND sample_path LIKE '%.cs'
      AND content CONTAINS 'MySqlGeometry'

1   zlzforever/DotnetSpider     src/MySql.Data/Field.cs  
2   mysql/mysql-connector-net   Source/MySql.Data/Field.cs   
3   mysql/mysql-connector-net   Tests/MySql.Data.Tests/DataTypeTests.cs 

My recommendation is that we remove the 1.0 tag and put this on the backlog. Once .NET core has spatial abstractions, we can either accept a contribution for it, or document a third-party library that supports it well if one emerges.

We should still add support for the spatial types as binary objects, and let callers cast from binary on Read and to binary before Write.

[enkodellc]

Here is what I used for EF 6, .Net Core 6:

            services.AddDbContext<AWSMariaSQLDbContext>(options => options.UseMySql(configuration.GetConnectionString("AWSMariaSQLDataConnection"), Microsoft.EntityFrameworkCore.ServerVersion.Parse("10.6.10-mariadb"), 
                options => options.UseNetTopologySuite())
            );

Then in my model builder:

        entity.Property(e => e.Location)
               .HasColumnName("Location")
               .HasColumnType("point");

My Model:

public Point Location { get; set; }