LineString conversion

A route contains an ordered sequence of points. AsLineString() stores that sequence using plain JSON string conversion; BaseDbContext does not apply it automatically.

Define and configure a route

Model declaration:

using Cratis.Geospatial;

public class DeliveryRoute
{
    public int Id { get; set; }
    public required LineString Path { get; set; }
}

In your context’s OnModelCreating, with Cratis.Arc.EntityFrameworkCore and Microsoft.EntityFrameworkCore imported:

modelBuilder.Entity<DeliveryRoute>().Property(route => route.Path).AsLineString();

A construction fragment for use inside a method:

var route = new LineString([
    new Point(-122.4194, 37.7749),
    new Point(-122.4185, 37.7750)
]);

The converter’s plain System.Text.Json output is:

{"Coordinates":[{"Longitude":-122.4194,"Latitude":37.7749},{"Longitude":-122.4185,"Latitude":37.775}]}

This is not GeoJSON. The type and converter do not enforce the minimum two points needed for a valid geographic line. Validate the sequence before persisting it.

Storage and queries

AsLineString() sets a value converter, not a SQL column type, spatial index, or structural value comparer. Do not assume record equality on coordinate arrays compares their contents, or that nested-coordinate LINQ expressions translate to SQL. Test any equality/change-tracking behavior your application depends on.

There is no LineStringColumn() helper for CreateTable. The separate AddLineStringColumn() migration helper declares geometry(LineString, 4326) on PostgreSQL, geography on SQL Server, and TEXT on SQLite. It does not make the string converter compatible with native spatial columns.

Use the storage-path matrix to choose between explicit string conversion, [Json], and application-configured native spatial mapping. Continue with Polygon conversion for areas.