Examples with DoNothingOperationObserver org.apache.cayenne.access.util.DoNothingOperationObserver used on opensource projects

Example 1 with DoNothingOperationObserver

use of org.apache.cayenne.access.util.DoNothingOperationObserver in project cayenne by apache.

the class FrontBasePkGenerator method longPkFromDatabase.

/**
 * @since 3.0
 */
@Override
protected long longPkFromDatabase(DataNode node, DbEntity entity) throws Exception {
    String template = "SELECT #result('UNIQUE' 'long') FROM " + entity.getName();
    final long[] pkHolder = new long[1];
    SQLTemplate query = new SQLTemplate(entity, template);
    OperationObserver observer = new DoNothingOperationObserver() {

        @Override
        public void nextRows(Query query, List<?> dataRows) {
            if (dataRows.size() != 1) {
                throw new CayenneRuntimeException("Error fetching PK. Expected one row, got %d", dataRows.size());
            }
            DataRow row = (DataRow) dataRows.get(0);
            Number pk = (Number) row.get("UNIQUE");
            pkHolder[0] = pk.longValue();
        }
    };
    node.performQueries(Collections.singleton((Query) query), observer);
    return pkHolder[0];
}