ClickHouse/dbms/src/Storages/System/StorageSystemOne.cpp

40 lines
990 B
C++

#include <Common/Exception.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataStreams/OneBlockInputStream.h>
#include <Storages/System/StorageSystemOne.h>
namespace DB
{
StorageSystemOne::StorageSystemOne(const std::string & name_)
: name(name_)
{
columns = NamesAndTypesList{{"dummy", std::make_shared<DataTypeUInt8>()}};
}
BlockInputStreams StorageSystemOne::read(
const Names & column_names,
const SelectQueryInfo &,
const Context &,
QueryProcessingStage::Enum & processed_stage,
const size_t /*max_block_size*/,
const unsigned /*num_streams*/)
{
check(column_names);
processed_stage = QueryProcessingStage::FetchColumns;
return BlockInputStreams(1, std::make_shared<OneBlockInputStream>(
Block{ColumnWithTypeAndName(
DataTypeUInt8().createColumnConst(1, UInt64(0))->convertToFullColumnIfConst(),
std::make_shared<DataTypeUInt8>(),
"dummy")}));
}
}