public DataPoint GetLastValues(string stationId, string sensorType)
{
using (var context = new WeatherStationDbContext(_nameOrConnectionString))
{
return(TryGetLatestDataPointForStationIdAndSensorType(context, stationId, sensorType));
}
}
public List <DataPoint> GetLastValues(string stationId)
{
using (var context = new WeatherStationDbContext(_nameOrConnectionString))
{
return(SensorDetails
.GetSensorTypeValues()
.Select(sensorType => TryGetLatestDataPointForStationIdAndSensorType(context, stationId, sensorType))
.Where(dp => dp != null)
.ToList());
}
}
private static DataPoint TryGetLatestDataPointForStationIdAndSensorType(
WeatherStationDbContext context,
string stationId,
string sensorType)
{
const string sql = @"SELECT TOP 1 *
FROM DataPoints
WHERE StationId = @stationId AND SensorType = @sensorType
ORDER BY SensorTimestampUtc DESC";
var dataPoint = context.DataPoints
.SqlQuery(sql, new SqlParameter("stationId", stationId), new SqlParameter("sensorType", sensorType))
.FirstOrDefault();
return(dataPoint);
}
