org.apache.metamodel.query.Query.getSelectClause()方法的使用及代码示例

x33g5p2x  于2022-01-28 转载在 其他  
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本文整理了Java中org.apache.metamodel.query.Query.getSelectClause方法的一些代码示例，展示了Query.getSelectClause的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Query.getSelectClause方法的具体详情如下：
包路径：org.apache.metamodel.query.Query
类名称：Query
方法名：getSelectClause

Query.getSelectClause介绍

暂无

代码示例

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

private static List<SelectItem> getSelectItems(List<Query> splitQueries) {
  if (splitQueries.isEmpty()) {
    return new ArrayList<SelectItem>(0);
  }
  return splitQueries.get(0).getSelectClause().getItems();
}

代码示例来源：origin: apache/metamodel

private static List<SelectItem> getSelectItems(List<Query> splitQueries) {
  if (splitQueries.isEmpty()) {
    return new ArrayList<SelectItem>(0);
  }
  return splitQueries.get(0).getSelectClause().getItems();
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

protected List<SelectItem> getSelectItems() {
  return _query.getSelectClause().getItems();
}

代码示例来源：origin: apache/metamodel

protected List<SelectItem> getSelectItems() {
  return _query.getSelectClause().getItems();
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

@Override
protected String rewriteSelectClause(Query query, SelectClause selectClause) {
  String result = super.rewriteSelectClause(query, selectClause);
  Integer maxRows = query.getMaxRows();
  if (maxRows != null) {
    if (query.getSelectClause().isDistinct()) {
      result = "SELECT DISTINCT TOP " + maxRows + " " + result.substring("SELECT DISTINCT ".length());
    } else {
      result = "SELECT TOP " + maxRows + " " + result.substring("SELECT ".length());
    }
  }
  return result;
}

代码示例来源：origin: apache/metamodel

@Override
protected String rewriteSelectClause(Query query, SelectClause selectClause) {
  String result = super.rewriteSelectClause(query, selectClause);
  Integer maxRows = query.getMaxRows();
  if (maxRows != null) {
    if (query.getSelectClause().isDistinct()) {
      result = "SELECT DISTINCT TOP " + maxRows + " " + result.substring("SELECT DISTINCT ".length());
    } else {
      result = "SELECT TOP " + maxRows + " " + result.substring("SELECT ".length());
    }
  }
  return result;
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

/**
 * Gets the size of a row (in bytes).
 * 
 * @param query
 *            the query that will yield the rows
 * @return an integer representing the size of a row from the given query
 *         (in bytes).
 */
protected int getRowSize(Query query) {
  List<SelectItem> items = query.getSelectClause().getItems();
  int bytesPerRow = 0;
  for (SelectItem selectItem : items) {
    bytesPerRow += getValueSize(selectItem);
  }
  return bytesPerRow;
}

代码示例来源：origin: apache/metamodel

/**
 * Gets the size of a row (in bytes).
 * 
 * @param query
 *            the query that will yield the rows
 * @return an integer representing the size of a row from the given query
 *         (in bytes).
 */
protected int getRowSize(Query query) {
  List<SelectItem> items = query.getSelectClause().getItems();
  int bytesPerRow = 0;
  for (SelectItem selectItem : items) {
    bytesPerRow += getValueSize(selectItem);
  }
  return bytesPerRow;
}

代码示例来源：origin: org.apache.metamodel/MetaModel-core

/**
 * This method returns the select item of the given alias name.
 * 
 * @param query
 * @return
 */
public static SelectItem getSelectItemByAlias(Query query, String alias) {
  List<SelectItem> selectItems = query.getSelectClause().getItems();
  for (SelectItem selectItem : selectItems) {
    if (selectItem.getAlias() != null && selectItem.getAlias().equals(alias)) {
      return selectItem;
    }
  }
  return null;
}

代码示例来源：origin: apache/metamodel

/**
 * This method returns the select item of the given alias name.
 * 
 * @param query
 * @return
 */
public static SelectItem getSelectItemByAlias(Query query, String alias) {
  List<SelectItem> selectItems = query.getSelectClause().getItems();
  for (SelectItem selectItem : selectItems) {
    if (selectItem.getAlias() != null && selectItem.getAlias().equals(alias)) {
      return selectItem;
    }
  }
  return null;
}

代码示例来源：origin: apache/metamodel

public String rewriteQuery(Query query) {
  query = beforeRewrite(query);
  final StringBuilder sb = new StringBuilder();
  sb.append(rewriteSelectClause(query, query.getSelectClause()));
  sb.append(rewriteFromClause(query, query.getFromClause()));
  sb.append(rewriteWhereClause(query, query.getWhereClause()));
  sb.append(rewriteGroupByClause(query, query.getGroupByClause()));
  sb.append(rewriteHavingClause(query, query.getHavingClause()));
  sb.append(rewriteOrderByClause(query, query.getOrderByClause()));
  return sb.toString();
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

public String rewriteQuery(Query query) {
  query = beforeRewrite(query);
  final StringBuilder sb = new StringBuilder();
  sb.append(rewriteSelectClause(query, query.getSelectClause()));
  sb.append(rewriteFromClause(query, query.getFromClause()));
  sb.append(rewriteWhereClause(query, query.getWhereClause()));
  sb.append(rewriteGroupByClause(query, query.getGroupByClause()));
  sb.append(rewriteHavingClause(query, query.getHavingClause()));
  sb.append(rewriteOrderByClause(query, query.getOrderByClause()));
  return sb.toString();
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

/**
 * Gets whether a query is guaranteed to only yield a single row. Such
 * queries are queries that only consist of aggregation functions and no
 * group by clause.
 * 
 * @param query
 * @return
 */
private boolean isSingleRowQuery(Query query) {
  if (!query.getGroupByClause().isEmpty()) {
    return false;
  }
  List<SelectItem> items = query.getSelectClause().getItems();
  for (SelectItem item : items) {
    if (item.getAggregateFunction() == null) {
      return false;
    }
  }
  return true;
}

代码示例来源：origin: apache/metamodel

/**
 * Gets whether a query is guaranteed to only yield a single row. Such
 * queries are queries that only consist of aggregation functions and no
 * group by clause.
 * 
 * @param query
 * @return
 */
private boolean isSingleRowQuery(Query query) {
  if (!query.getGroupByClause().isEmpty()) {
    return false;
  }
  List<SelectItem> items = query.getSelectClause().getItems();
  for (SelectItem item : items) {
    if (item.getAggregateFunction() == null) {
      return false;
    }
  }
  return true;
}

代码示例来源：origin: datacleaner/DataCleaner

public SimpleDictionary loadIntoMemory(final DatastoreConnection datastoreConnection) {
  final DataContext dataContext = datastoreConnection.getDataContext();
  final Column column = getColumn(datastoreConnection);
  final Query query = dataContext.query().from(column.getTable()).select(column).toQuery();
  if (datastoreConnection.getDatastore().getPerformanceCharacteristics().isQueryOptimizationPreferred()) {
    query.getSelectClause().setDistinct(true);
  }
  final Set<String> values = new HashSet<>();
  try (DataSet dataSet = dataContext.executeQuery(query)) {
    while (dataSet.next()) {
      final Object value = dataSet.getRow().getValue(0);
      if (value != null) {
        values.add(value.toString());
      }
    }
  }
  return new SimpleDictionary(getName(), values);
}

代码示例来源：origin: org.apache.metamodel/MetaModel-jdbc

private long getRowCount(Query q) {
  q = q.clone();
  SelectItem countAllItem = SelectItem.getCountAllItem();
  if (q.getGroupByClause().getItemCount() > 0) {
    q = new Query().from(new FromItem(q).setAlias("sq")).select(countAllItem);
  } else {
    q.getSelectClause().removeItems();
    q.select(countAllItem);
  }
  Row row = MetaModelHelper.executeSingleRowQuery(_dataContext, q);
  Number count = (Number) row.getValue(countAllItem);
  return count.longValue();
}

代码示例来源：origin: apache/metamodel

private long getRowCount(Query q) {
  q = q.clone();
  SelectItem countAllItem = SelectItem.getCountAllItem();
  if (q.getGroupByClause().getItemCount() > 0) {
    q = new Query().from(new FromItem(q).setAlias("sq")).select(countAllItem);
  } else {
    q.getSelectClause().removeItems();
    q.select(countAllItem);
  }
  Row row = MetaModelHelper.executeSingleRowQuery(_dataContext, q);
  Number count = (Number) row.getValue(countAllItem);
  return count.longValue();
}

代码示例来源：origin: datacleaner/DataCleaner

public void initialize() {
  final Table table = _outputDataStreamJob.getOutputDataStream().getTable();
  final Query query = new Query();
  query.from(table).selectAll();
  final List<SelectItem> selectItems = query.getSelectClause().getItems();
  final ConsumeRowHandler consumeRowHandler = _publisher.createConsumeRowHandler();
  _outputRowCollector = new OutputDataStreamRowCollector(_publisher, selectItems, consumeRowHandler);
  final OutputDataStream outputDataStream = _outputDataStreamJob.getOutputDataStream();
  _component.initializeOutputDataStream(outputDataStream, query, _outputRowCollector);
  _publisher.getAnalysisListener()
      .rowProcessingBegin(_publisher.getAnalysisJob(), _publisher.getRowProcessingMetrics());
}

代码示例来源：origin: org.apache.metamodel/MetaModel-core

public Query selectAll(final FromItem fromItem) {
  if (fromItem.getTable() != null) {
    final List<Column> columns = fromItem.getTable().getColumns();
    for (final Column column : columns) {
      select(column, fromItem);
    }
  } else if (fromItem.getJoin() != null) {
    selectAll(fromItem.getLeftSide());
    selectAll(fromItem.getRightSide());
  } else if (fromItem.getSubQuery() != null) {
    final List<SelectItem> items = fromItem.getSubQuery().getSelectClause().getItems();
    for (final SelectItem subQuerySelectItem : items) {
      select(new SelectItem(subQuerySelectItem, fromItem));
    }
  } else {
    throw new MetaModelException("All select items ('*') not determinable with from item: " + fromItem);
  }
  return this;
}

代码示例来源：origin: apache/metamodel

public Query selectAll(final FromItem fromItem) {
  if (fromItem.getTable() != null) {
    final List<Column> columns = fromItem.getTable().getColumns();
    for (final Column column : columns) {
      select(column, fromItem);
    }
  } else if (fromItem.getJoin() != null) {
    selectAll(fromItem.getLeftSide());
    selectAll(fromItem.getRightSide());
  } else if (fromItem.getSubQuery() != null) {
    final List<SelectItem> items = fromItem.getSubQuery().getSelectClause().getItems();
    for (final SelectItem subQuerySelectItem : items) {
      select(new SelectItem(subQuerySelectItem, fromItem));
    }
  } else {
    throw new MetaModelException("All select items ('*') not determinable with from item: " + fromItem);
  }
  return this;
}

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