static UsageDataMessage FetchDataForUpload(SQLiteConnection connection, bool fetchIncompleteSessions)
        {
            UsageDataMessage message = new UsageDataMessage();
            // Retrieve the User ID
            using (SQLiteCommand cmd = connection.CreateCommand()) {
                cmd.CommandText = "SELECT value FROM Properties WHERE name = 'userID';";
                string userID = (string)cmd.ExecuteScalar();
                message.UserID = new Guid(userID);
            }

            // Retrieve the list of sessions
            using (SQLiteCommand cmd = connection.CreateCommand()) {
                if (fetchIncompleteSessions) {
                    cmd.CommandText = @"SELECT id, startTime, endTime FROM Sessions;";
                } else {
                    // Fetch all sessions which are either closed or inactive for more than 24 hours
                    cmd.CommandText = @"SELECT id, startTime, endTime FROM Sessions
                        WHERE (endTime IS NOT NULL)
                            OR (ifnull((SELECT max(time) FROM FeatureUses WHERE FeatureUses.session = Sessions.id), Sessions.startTime)
                                < datetime('now','-1 day'));";
                }
                using (SQLiteDataReader reader = cmd.ExecuteReader()) {
                    while (reader.Read()) {
                        UsageDataSession session = new UsageDataSession();
                        session.SessionID = reader.GetInt64(0);
                        session.StartTime = reader.GetDateTime(1);
                        if (!reader.IsDBNull(2))
                            session.EndTime = reader.GetDateTime(2);
                        message.Sessions.Add(session);
                    }
                }
            }
            string commaSeparatedSessionIDList = GetCommaSeparatedIDList(message.Sessions);

            StringInterner stringInterning = new StringInterner();
            // Retrieve the environment
            using (SQLiteCommand cmd = connection.CreateCommand()) {
                cmd.CommandText = "SELECT session, name, value FROM Environment WHERE session IN (" + commaSeparatedSessionIDList + ");";
                using (SQLiteDataReader reader = cmd.ExecuteReader()) {
                    while (reader.Read()) {
                        long sessionID = reader.GetInt64(0);
                        UsageDataSession session = message.FindSession(sessionID);
                        session.EnvironmentProperties.Add(
                            new UsageDataEnvironmentProperty {
                                Name = stringInterning.Intern(reader.GetString(1)),
                                Value = stringInterning.Intern(reader.GetString(2))
                            });
                    }
                }
            }

            // Retrieve the feature uses
            using (SQLiteCommand cmd = connection.CreateCommand()) {
                cmd.CommandText = "SELECT session, time, endTime, feature, activationMethod FROM FeatureUses WHERE session IN (" + commaSeparatedSessionIDList + ");";
                using (SQLiteDataReader reader = cmd.ExecuteReader()) {
                    while (reader.Read()) {
                        long sessionID = reader.GetInt64(0);
                        UsageDataSession session = message.FindSession(sessionID);
                        UsageDataFeatureUse featureUse = new UsageDataFeatureUse();
                        featureUse.Time = reader.GetDateTime(1);
                        if (!reader.IsDBNull(2))
                            featureUse.EndTime = reader.GetDateTime(2);
                        featureUse.FeatureName = stringInterning.Intern(reader.GetString(3));
                        if (!reader.IsDBNull(4))
                            featureUse.ActivationMethod = stringInterning.Intern(reader.GetString(4));
                        session.FeatureUses.Add(featureUse);
                    }
                }
            }

            // Retrieve the exceptions
            using (SQLiteCommand cmd = connection.CreateCommand()) {
                cmd.CommandText = "SELECT session, time, type, stackTrace FROM Exceptions WHERE session IN (" + commaSeparatedSessionIDList + ");";
                using (SQLiteDataReader reader = cmd.ExecuteReader()) {
                    while (reader.Read()) {
                        long sessionID = reader.GetInt64(0);
                        UsageDataSession session = message.FindSession(sessionID);
                        UsageDataException exception = new UsageDataException();
                        exception.Time = reader.GetDateTime(1);
                        exception.ExceptionType = stringInterning.Intern(reader.GetString(2));
                        if (!reader.IsDBNull(3))
                            exception.StackTrace = stringInterning.Intern(reader.GetString(3));
                        session.Exceptions.Add(exception);
                    }
                }
            }

            return message;
        }
 public ExceptionImport(UsageDataException ude)
     : this(ude.ExceptionType, ude.StackTrace, ude.Time)
 {
 }