/**
* @return Numeric meta data information for the channel or <code>null</code>
* @throws Exception on error
*/
private Display determineDisplay() throws Exception {
// Try numeric meta data
final PreparedStatement statement =
reader.getConnection().prepareStatement(reader.getSQL().numeric_meta_sel_by_channel);
try {
statement.setInt(1, channel_id);
final ResultSet result = statement.executeQuery();
if (result.next()) {
final NumberFormat format = NumberFormats.format(result.getInt(7)); // prec
return ValueFactory.newDisplay(
result.getDouble(1), // lowerDisplayLimit
result.getDouble(5), // lowerAlarmLimit
result.getDouble(3), // lowerWarningLimit
result.getString(8), // units
format, // numberFormat
result.getDouble(4), // upperWarningLimit
result.getDouble(6), // upperAlarmLimit
result.getDouble(2), // upperDisplayLimit
result.getDouble(1), // lowerCtrlLimit
result.getDouble(2)); // upperCtrlLimit
}
} finally {
statement.close();
}
// No numeric display meta data
return null;
}
/**
* @param reader RDBArchiveReader
* @param channel_id ID of channel
* @throws Exception on error
*/
AbstractRDBValueIterator(final RDBArchiveReader reader, final int channel_id) throws Exception {
this.reader = reader;
this.channel_id = channel_id;
try {
this.display = determineDisplay();
this.labels = determineLabels();
} catch (final Exception ex) {
// Set iterator to empty
close();
if (!RDBArchiveReader.isCancellation(ex)) throw ex;
// Else: Not a real error, return empty iterator
}
if (labels == null && display == null)
display =
ValueFactory.newDisplay(
0.0, 0.0, 0.0, "", NumberFormats.format(0), 0.0, 0.0, 10.0, 0.0, 10.0);
}