private static String createSqlFrom(ListingDescriptor listing)
throws ModelException, PersistenceException, SQLException
{
PersistentDescriptor persistents = listing.getPersistents();
StringBuffer sql = new StringBuffer("");
Iterator iKey = persistents.keyIterator();
if (! iKey.hasNext())
{
throw new ModelException("No persistents defined for listing " + listing.getHeader());
}