Java Query.setResult方法代碼示例

import javax.jdo.Query; //導入方法依賴的package包/類
/**
 * Given a query, this method will decorate that query with pagination, ordering,
 * and sorting direction. Specific checks are performed to ensure the execution
 * of the query is capable of being paged and that ordering can be securely performed.
 * @param query the JDO Query object to execute
 * @return a Collection of objects
 * @since 1.0.0
 */
public Query decorate(final Query query) {
    // Clear the result to fetch if previously specified (i.e. by getting count)
    query.setResult(null);
    if (pagination != null && pagination.isPaginated()) {
        final long begin = pagination.getOffset();
        final long end = begin + pagination.getLimit();
        query.setRange(begin, end);
    }
    if (orderBy != null && RegexSequence.Pattern.ALPHA_NUMERIC.matcher(orderBy).matches() && orderDirection != OrderDirection.UNSPECIFIED) {
        // Check to see if the specified orderBy field is defined in the class being queried.
        boolean found = false;
        final org.datanucleus.store.query.Query iq = ((JDOQuery) query).getInternalQuery();
        for (Field field: iq.getCandidateClass().getDeclaredFields()) {
            if (orderBy.equals(field.getName())) {
                found = true;
                break;
            }
        }
        if (found) {
            query.setOrdering(orderBy + " " + orderDirection.name().toLowerCase());
        }
    }
    return query;
}
 

import javax.jdo.Query; //導入方法依賴的package包/類
public Long getShortId(Long kioskId) {
  PersistenceManager pm = PMF.get().getPersistenceManager();
  Query q = null;
  try {
    q = pm.newQuery(JDOUtils.getImplClass(IInvntry.class));
    q.setResult("max(sId)");
    q.setFilter("kId == " + kioskId);
    Long count = (Long) q.execute();
    return count == null ? -1 : count;
  } catch (Exception e) {
    xLogger.warn("Error while getting short id for kiosk {0}", kioskId, e);
    return null;
  } finally {
    if (q != null) {
      try {
        q.closeAll();
      } catch (Exception ignored) {
        xLogger.warn("Exception while closing query", ignored);
      }
    }
    if (pm != null) {
      pm.close();
    }
  }
}
 

import javax.jdo.Query; //導入方法依賴的package包/類
private static int getCnt(Query query, Object o1, Object o2, Map map) {
  if (query == null) {
    return -1;
  }
  query.setResult(QueryConstants.COUNT);
  query.setRange(null);
  query.setOrdering(null);
  Long cnt;
  if (map != null) {
    cnt = (Long) query.executeWithMap(map);
  } else {
    cnt = (Long) query.execute(o1, o2);
  }
  return Integer.parseInt(String.valueOf(cnt));

}
 

import javax.jdo.Query; //導入方法依賴的package包/類
/**
 * Returns the number of items that would have resulted from returning all object.
 * This method is performant in that the objects are not actually retrieved, only
 * the count.
 * @param query the query to return a count from
 * @return the number of items
 * @since 1.0.0
 */
public long getCount(final Query query) {
    //query.addExtension("datanucleus.query.resultSizeMethod", "count");
    final String ordering = ((org.datanucleus.api.jdo.JDOQuery) query).getInternalQuery().getOrdering();
    query.setResult("count(id)");
    query.setOrdering(null);
    final long count = (Long) query.execute();
    query.setOrdering(ordering);
    return count;
}