Query a feature layer with a parameter of type Date

Question

Hi, I created a special Feature Collection with a table which contains a Date field. //Create a feature collection and store it in a feature collection layer var fields = new List<Field> {new Field(FieldType.Date, "Date", "Date", 20)}; var table = new FeatureCollectionTable(fields, GeometryType.Point, SpatialReferences.Wgs84); table.Renderer = new SimpleRenderer(new SimpleMarkerSymbol{Color = Color.Blue, Size = 5}); var collection = new FeatureCollection(new [] {table}); var collectionLayer = new FeatureCollectionLayer(collection){Id = "FeatureCollectionLayer" }; var feature = table.CreateFeature(); feature.Geometry = new MapPoint(11.6,48.1, SpatialReferences.Wgs84); feature.Attributes["Date"] = DefaultDate; await table.AddFeatureAsync(feature); Map.OperationalLayers.Add(collectionLayer);‍‍‍‍‍‍‍‍‍‍‍‍‍ Now: When I want to Query this feature layer, I am not able to get a result match for my search date: //Now load try to query on this layer with a where clause on the date field var layer = ((FeatureCollectionLayer)Map.OperationalLayers["FeatureCollectionLayer"]).Layers.First(); var result = await layer.FeatureTable.QueryFeaturesAsync(new QueryParameters() { WhereClause = $"Date = '{DefaultDate}'" }); layer.SelectFeatures(result);‍‍‍‍‍‍‍ The result is always empty, no selection was made. DefaultDate by the way is a static value: public DateTime DefaultDate { get; set; } = new DateTime(2019, 05, 08, 6, 0, 0);‍ In the end I used int32 instead of Date as the data type for the field and converted the date into an integer, so it finally worked. So my questions are: * Why does it not work with data type Date? What was wrong here? * Why does data type Date needs a length when creating the field? What is it for? Is it used? * I missed a data type boolean. Any reasons why it is missing? Kind regards Max

MaxGlas · Accepted Answer

Ok, we got it: var result = await layer.FeatureTable.QueryFeaturesAsync(new QueryParameters() { WhereClause = $"datetime(Date, 'utc') = datetime('{DefaultDate.ToString("s", new CultureInfo("en-us"))}', 'utc')" });‍‍‍‍ A bit tricky that doubly conversion of both sides regarding the correct date format and UTC time. But this way it worked for us.