if (dtUri.equals(XSD.date.toString())) {
// Date column
return new DateColumn(var, nullable);
} else if (dtUri.equals(XSD.dateTime.toString())) {
// Date time column
return new DateTimeColumn(var, nullable);
} else if (dtUri.equals(XSD.decimal.toString())) {
// Decimal column
return new DecimalColumn(var, nullable);
} else if (dtUri.equals(XSD.duration.toString())) {
// JDBC has no notion of durations so return as a string