Point conversion

To store a location, first choose its representation. Arc’s AsPoint() converts a Cratis.Geospatial.Point to a JSON string; it does not install a native spatial provider or select a JSON SQL column type. BaseDbContext does not call it automatically.

Configure string conversion

These are complete model/context declarations. This example derives from plain DbContext, which Arc’s automatic discovery does not discover. Register it explicitly in your configured Arc host and apply your schema separately.

using Cratis.Arc.EntityFrameworkCore;
using Cratis.Geospatial;
using Microsoft.EntityFrameworkCore;

public class Store
{
    public int Id { get; set; }
    public required Point Location { get; set; }
}

public class StoreDbContext(DbContextOptions<StoreDbContext> options) : DbContext(options)
{
    public DbSet<Store> Stores => Set<Store>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Store>().Property(store => store.Location).AsPoint();
        base.OnModelCreating(modelBuilder);
    }
}

After declaring the context, add this startup fragment, where services is the host’s IServiceCollection:

using Cratis.Arc.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

services.AddDbContextWithConnectionString<StoreDbContext>("Data Source=store.db");

AsPoint() takes no database argument. It uses plain System.Text.Json, not MongoDB’s GeoJSON serializer. For new Point(Longitude: -122.4194, Latitude: 37.7749), the converted value is:

{"Longitude":-122.4194,"Latitude":37.7749}

The converter does not validate coordinate ranges. Validate longitude/latitude in your application. EF normally handles a null property without passing it through the value converter; choose property and column nullability consistently.

Choose one storage path

Path	Configuration	Storage contract
String conversion	Explicit AsPoint(), AsLineString(), or AsPolygon()	Plain JSON string; SQL type comes from the EF string mapping or your explicit configuration
JSON property	[Json] with BaseDbContext or ApplyJsonConversion	JSON conversion options and provider-specific JSON column mapping; see JSON conversion
Spatial migration	AddPointColumn, AddLineStringColumn, AddPolygonColumn	Spatial SQL type declarations on PostgreSQL/SQL Server, text on SQLite; not a geometry value converter

Do not apply both string and [Json] conversion to the same property. Their serializer options are separate. Neither path promises translated distance, intersection, or nested-coordinate LINQ queries.

Migration usage

Arc has no PointColumn() helper for CreateTable. A string-converted point can use an ordinary string column, aligned with your model mapping. The separate MigrationBuilder.AddPointColumn method selects:

PostgreSQL	SQL Server	SQLite
geometry(Point, 4326)	geography	TEXT

This is a schema helper, not a complete native spatial recipe. Pairing its PostgreSQL/SQL Server columns with AsPoint() is not supported by an automatic adapter. Native spatial usage requires a compatible provider mapping, database prerequisites (such as PostGIS), migrations, and round-trip tests designed by your application.

See adding columns, LineString conversion, and Polygon conversion.