/// <summary>
/// Searches for matching telemetry event data in the data store.
/// </summary>
/// <param name="filter">Optional filter options to apply to the telemetry event data search.</param>
public async Task <IEnumerable <TelemetryEvent <TContext> > > SearchDataAsync(FilterOptions filter = null)
{
List <TelemetryEvent <TContext> > events = new List <TelemetryEvent <TContext> >();
try
{
using (MySqlConnection connection = new MySqlConnection(this.sqlConnectionString))
{
using (MySqlCommand command = this.CreateTelemetrySearchCommand(connection, filter))
{
await connection.OpenAsync().ConfigureAwait(false);
using (IDataReader reader = await command.ExecuteReaderAsync().ConfigureAwait(false))
{
if (reader != null)
{
while (reader.Read())
{
events.Add(new TelemetryEvent <TContext>(
eventName: reader.GetString(1),
correlationId: reader.GetGuid(2),
timestamp: reader.GetDateTime(0),
context: JsonConvert.DeserializeObject <TContext>(reader.GetString(3), TelemetryEvent <TContext> .SerializationSettings)));
}
}
}
}
}
}
catch
{
throw;
}
return(events as IEnumerable <TelemetryEvent <TContext> >);
}
protected MySqlCommand CreateTelemetrySearchCommand(MySqlConnection connection, FilterOptions filter)
{
MySqlCommand command = connection.CreateCommand();
command.CommandType = System.Data.CommandType.Text;
command.CommandText =
@"SELECT
Timestamp,
EventName,
CorrelationId,
Context
FROM TelemetryEvents
WHERE 1";
if (filter != null && filter.IsSet)
{
if (filter.CorrelationId != null)
{
command.CommandText += $" AND CorrelationId = '{filter.CorrelationId}'";
}
if (filter.EventName != null)
{
command.CommandText += $" AND EventName = '{filter.EventName}'";
}
if (filter.Latest == true)
{
if (filter.EventName != null)
{
command.CommandText +=
$@" AND CorrelationId =
(
SELECT CorrelationId FROM TelemetryEvents
WHERE EventName = '{filter.EventName}'
ORDER BY Id DESC
LIMIT 1
) ORDER BY TIMESTAMP DESC";
}
else
{
command.CommandText +=
$@" AND CorrelationId =
(
SELECT CorrelationId FROM TelemetryEvents
ORDER BY Id DESC
LIMIT 1
) ORDER BY TIMESTAMP DESC";
}
}
}
else
{
command.CommandText += " ORDER BY TIMESTAMP DESC LIMIT 300";
}
return(command);
}
