# Query ## Execute a multi-step query pipeline `QueryExecuteResponse Query.Execute(QueryExecuteParamsparameters, CancellationTokencancellationToken = default)` **post** `/api/v1/query` Execute a multi-step query pipeline ### Parameters - `QueryExecuteParams parameters` - `required IReadOnlyList steps` Ordered list of query steps to execute - `required Type Type` Step type: `overpass`, `sparql`, `filter`, or `transform` - `"overpass"Overpass` - `"sparql"Sparql` - `"filter"Filter` - `"transform"Transform` - `string Query` Query string for this step (required for overpass/sparql steps) ### Returns - `class QueryExecuteResponse:` Pipeline execution result containing the output of each step. - `required IReadOnlyList> Steps` Results from each pipeline step in execution order ### Example ```csharp QueryExecuteParams parameters = new() { Steps = [ new() { Type = Type.Overpass, Query = "query", }, ], }; var response = await client.Query.Execute(parameters); Console.WriteLine(response); ``` #### Response ```json { "steps": [ { "foo": "bar" } ] } ``` ## Execute an Overpass QL query `FeatureCollection Query.Overpass(QueryOverpassParamsparameters, CancellationTokencancellationToken = default)` **post** `/api/v1/overpass` Execute an Overpass QL query ### Parameters - `QueryOverpassParams parameters` - `required string data` Overpass QL query string ### Returns - `class FeatureCollection:` GeoJSON FeatureCollection (RFC 7946). For paginated endpoints, metadata is returned in HTTP response headers rather than the body: | Header | Description | | --------------- | ------------------------------------------------ | | `X-Limit` | Requested result limit | | `X-Has-More` | `true` if more results exist | | `X-Next-Cursor` | Opaque cursor for next page (cursor pagination) | | `X-Next-Offset` | Numeric offset for next page (offset pagination) | | `Link` | RFC 8288 `rel="next"` link to the next page | Content-Type is `application/geo+json`. - `required IReadOnlyList Features` Array of GeoJSON Feature objects - `required GeoJsonGeometry Geometry` GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints. - `required Coordinates Coordinates` Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc. - `IReadOnlyList` - `IReadOnlyList>` - `IReadOnlyList>>` - `IReadOnlyList>>>` - `required Type Type` Geometry type - `"Point"Point` - `"LineString"LineString` - `"Polygon"Polygon` - `"MultiPoint"MultiPoint` - `"MultiLineString"MultiLineString` - `"MultiPolygon"MultiPolygon` - `required IReadOnlyDictionary Properties` OSM tags flattened as key-value pairs, plus `@type` (node/way/relation) and `@id` (OSM ID) metadata fields. May include `distance_m` for proximity queries. - `required Type Type` Always `Feature` - `"Feature"Feature` - `string ID` Compound identifier in `type/osm_id` format - `required Type Type` Always `FeatureCollection` - `"FeatureCollection"FeatureCollection` ### Example ```csharp QueryOverpassParams parameters = new() { Data = "[out:json];node[amenity=cafe](around:500,48.8566,2.3522);out body;" }; var featureCollection = await client.Query.Overpass(parameters); Console.WriteLine(featureCollection); ``` #### Response ```json { "features": [ { "geometry": { "coordinates": [ 2.3522, 48.8566 ], "type": "Point" }, "properties": { "@id": "bar", "@type": "bar", "amenity": "bar", "cuisine": "bar", "name": "bar" }, "type": "Feature", "id": "node/21154906" } ], "type": "FeatureCollection" } ``` ## Execute a SPARQL query `SparqlResult Query.Sparql(QuerySparqlParamsparameters, CancellationTokencancellationToken = default)` **post** `/api/v1/sparql` Execute a SPARQL query ### Parameters - `QuerySparqlParams parameters` - `required string query` SPARQL query string ### Returns - `class SparqlResult:` SPARQL query result. Contains a `results` array of GeoJSON Feature objects. Unlike REST feature endpoints, SPARQL results may omit `@type`, `@id`, and compound `id` fields depending on the query shape. - `required IReadOnlyList Results` Array of GeoJSON Features matching the SPARQL query. Features include `@type` and `@id` metadata when the source element type is known, but may contain only tags as properties for untyped results. - `required GeoJsonGeometry Geometry` GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints. - `required Coordinates Coordinates` Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc. - `IReadOnlyList` - `IReadOnlyList>` - `IReadOnlyList>>` - `IReadOnlyList>>>` - `required Type Type` Geometry type - `"Point"Point` - `"LineString"LineString` - `"Polygon"Polygon` - `"MultiPoint"MultiPoint` - `"MultiLineString"MultiLineString` - `"MultiPolygon"MultiPolygon` - `required IReadOnlyDictionary Properties` OSM tags as key-value pairs, optionally with `@type` and `@id` metadata - `required Type Type` Always `Feature` - `"Feature"Feature` - `string? ID` Compound identifier in `type/osm_id` format (present when element type is known) ### Example ```csharp QuerySparqlParams parameters = new() { Query = "SELECT ?s ?name WHERE { ?s osm:name ?name . ?s osm:amenity \"cafe\" } LIMIT 10", }; var sparqlResult = await client.Query.Sparql(parameters); Console.WriteLine(sparqlResult); ``` #### Response ```json { "results": [ { "geometry": { "coordinates": [ 2.3522, 48.8566 ], "type": "Point" }, "properties": { "foo": "bar" }, "type": "Feature", "id": "id" } ] } ``` ## Domain Types ### Overpass Query - `class OverpassQuery:` Overpass QL query request. The query is executed against Plaza's OSM database and results are returned as GeoJSON. - `required string Data` Overpass QL query string ### Sparql Query - `class SparqlQuery:` SPARQL query request. Queries OSM data using SPARQL syntax. Results are returned as a JSON object with a `results` array. - `required string Query` SPARQL query string ### Sparql Result - `class SparqlResult:` SPARQL query result. Contains a `results` array of GeoJSON Feature objects. Unlike REST feature endpoints, SPARQL results may omit `@type`, `@id`, and compound `id` fields depending on the query shape. - `required IReadOnlyList Results` Array of GeoJSON Features matching the SPARQL query. Features include `@type` and `@id` metadata when the source element type is known, but may contain only tags as properties for untyped results. - `required GeoJsonGeometry Geometry` GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints. - `required Coordinates Coordinates` Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc. - `IReadOnlyList` - `IReadOnlyList>` - `IReadOnlyList>>` - `IReadOnlyList>>>` - `required Type Type` Geometry type - `"Point"Point` - `"LineString"LineString` - `"Polygon"Polygon` - `"MultiPoint"MultiPoint` - `"MultiLineString"MultiLineString` - `"MultiPolygon"MultiPolygon` - `required IReadOnlyDictionary Properties` OSM tags as key-value pairs, optionally with `@type` and `@id` metadata - `required Type Type` Always `Feature` - `"Feature"Feature` - `string? ID` Compound identifier in `type/osm_id` format (present when element type is known)