/**
* Finds the minimum date.
*
* @param fieldName the field to look for the minimum date. If fieldName is not of Date type, an
* exception is thrown.
* @return if no objects exist or they all have {@code null} as the value for the given date
* field, {@code null} will be returned. Otherwise the minimum date is returned. When
* determining the minimum date, objects with {@code null} values are ignored.
* @throws java.lang.IllegalArgumentException if fieldName is not a Date field.
*/
public Date minDate(String fieldName) {
realm.checkIfValid();
long columnIndex = table.getColumnIndex(fieldName);
if (table.getColumnType(columnIndex) == RealmFieldType.DATE) {
return table.minimumDate(columnIndex);
} else {
throw new IllegalArgumentException(String.format(TYPE_MISMATCH, fieldName, "Date"));
}
}
