ClickHouse/dbms/src/Storages/System/StorageSystemColumns.h

37 lines
856 B
C++

#pragma once
#include <ext/shared_ptr_helper.h>
#include <Storages/System/IStorageSystemOneBlock.h>
namespace DB
{
class Context;
/** Implements system table 'columns', that allows to get information about columns for every table.
*/
class StorageSystemColumns : public ext::shared_ptr_helper<StorageSystemColumns>, public IStorage
{
public:
std::string getName() const override { return "SystemColumns"; }
std::string getTableName() const override { return name; }
BlockInputStreams read(
const Names & column_names,
const SelectQueryInfo & query_info,
const Context & context,
QueryProcessingStage::Enum processed_stage,
size_t max_block_size,
unsigned num_streams) override;
private:
const std::string name;
protected:
StorageSystemColumns(const std::string & name_);
};
}