ClickHouse/dbms/include/DB/Parsers/ASTSelectQuery.h

90 lines
3.7 KiB
C++

#pragma once
#include <DB/Parsers/IAST.h>
#include <DB/Parsers/ASTQueryWithOutput.h>
#include <DB/Parsers/ASTExpressionList.h>
#include <DB/Parsers/ASTFunction.h>
namespace DB
{
/** SELECT запрос
*/
class ASTSelectQuery : public ASTQueryWithOutput
{
public:
bool distinct;
ASTPtr select_expression_list;
ASTPtr database;
ASTPtr table; /// Идентификатор, табличная функция или подзапрос (рекурсивно ASTSelectQuery)
ASTPtr array_join_expression_list;
bool final;
ASTPtr sample_size;
ASTPtr prewhere_expression;
ASTPtr where_expression;
ASTPtr group_expression_list;
bool group_by_with_totals;
ASTPtr having_expression;
ASTPtr order_expression_list;
ASTPtr limit_offset;
ASTPtr limit_length;
ASTSelectQuery() : distinct(false), final(false), group_by_with_totals(false) {}
ASTSelectQuery(StringRange range_) : ASTQueryWithOutput(range_), distinct(false), final(false), group_by_with_totals(false) {}
/** Получить текст, который идентифицирует этот элемент. */
String getID() const { return "SelectQuery"; };
/// Переписывает select_expression_list, чтобы вернуть только необходимые столбцы в правильном порядке.
void rewriteSelectExpressionList(const Names & column_names)
{
ASTPtr result = new ASTExpressionList;
ASTs asts = select_expression_list->children;
for (size_t i = 0; i < column_names.size(); ++i)
{
bool done = 0;
for (size_t j = 0; j < asts.size(); ++j)
{
if (asts[j]->getAlias() == column_names[i])
{
result->children.push_back(asts[j]->clone());
done = 1;
}
}
if (!done)
throw Exception("Error while rewriting expressioin list for select query."
" Could not find alias: " + column_names[i],
DB::ErrorCodes::UNKNOWN_IDENTIFIER);
}
select_expression_list.swap(result);
}
ASTPtr clone() const
{
ASTSelectQuery * res = new ASTSelectQuery(*this);
res->children.clear();
if (select_expression_list) { res->select_expression_list = select_expression_list->clone(); res->children.push_back(res->select_expression_list); }
if (database) { res->database = database->clone(); res->children.push_back(res->database); }
if (table) { res->table = table->clone(); res->children.push_back(res->table); }
if (array_join_expression_list) { res->array_join_expression_list = array_join_expression_list->clone(); res->children.push_back(res->array_join_expression_list); }
if (sample_size) { res->sample_size = sample_size->clone(); res->children.push_back(res->sample_size); }
if (prewhere_expression) { res->prewhere_expression = prewhere_expression->clone(); res->children.push_back(res->prewhere_expression); }
if (where_expression) { res->where_expression = where_expression->clone(); res->children.push_back(res->where_expression); }
if (group_expression_list) { res->group_expression_list = group_expression_list->clone(); res->children.push_back(res->group_expression_list); }
if (having_expression) { res->having_expression = having_expression->clone(); res->children.push_back(res->having_expression); }
if (order_expression_list) { res->order_expression_list = order_expression_list->clone(); res->children.push_back(res->order_expression_list); }
if (limit_offset) { res->limit_offset = limit_offset->clone(); res->children.push_back(res->limit_offset); }
if (limit_length) { res->limit_length = limit_length->clone(); res->children.push_back(res->limit_length); }
if (format) { res->format = format->clone(); res->children.push_back(res->format); }
return res;
}
};
}