mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-09-21 09:10:48 +00:00
136 lines
4.3 KiB
C++
136 lines
4.3 KiB
C++
#pragma once
|
|
|
|
#include <DB/Core/Block.h>
|
|
#include <DB/DataStreams/IProfilingBlockInputStream.h>
|
|
#include <DB/DataTypes/DataTypesNumberFixed.h>
|
|
#include <DB/DataTypes/DataTypeString.h>
|
|
#include <DB/DataTypes/DataTypeDate.h>
|
|
#include <DB/DataTypes/DataTypeDateTime.h>
|
|
#include <DB/Columns/ColumnString.h>
|
|
#include <DB/Dictionaries/ExternalResultDescription.h>
|
|
|
|
#include <Poco/Data/Session.h>
|
|
#include <Poco/Data/Statement.h>
|
|
#include <Poco/Data/RecordSet.h>
|
|
|
|
#include <ext/range.hpp>
|
|
#include <vector>
|
|
#include <string>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int NUMBER_OF_COLUMNS_DOESNT_MATCH;
|
|
}
|
|
|
|
|
|
/// Allows processing results of a query to ODBC source as a sequence of Blocks, simplifies chaining
|
|
class ODBCBlockInputStream final : public IProfilingBlockInputStream
|
|
{
|
|
public:
|
|
ODBCBlockInputStream(
|
|
Poco::Data::Session && session, const std::string & query_str, const Block & sample_block,
|
|
const std::size_t max_block_size)
|
|
:
|
|
session{session},
|
|
statement{(this->session << query_str, Poco::Data::Keywords::now)},
|
|
result{statement},
|
|
iterator{result.begin()},
|
|
max_block_size{max_block_size}
|
|
{
|
|
if (sample_block.columns() != result.columnCount())
|
|
throw Exception{
|
|
"RecordSet contains " + toString(result.columnCount()) + " columns while " +
|
|
toString(sample_block.columns()) + " expected",
|
|
ErrorCodes::NUMBER_OF_COLUMNS_DOESNT_MATCH};
|
|
|
|
description.init(sample_block);
|
|
}
|
|
|
|
String getName() const override { return "ODBC"; }
|
|
|
|
String getID() const override
|
|
{
|
|
return "ODBC(" + statement.toString() + ")";
|
|
}
|
|
|
|
private:
|
|
using value_type_t = ExternalResultDescription::value_type_t;
|
|
|
|
|
|
Block readImpl() override
|
|
{
|
|
if (iterator == result.end())
|
|
return {};
|
|
|
|
auto block = description.sample_block.cloneEmpty();
|
|
|
|
/// cache pointers returned by the calls to getByPosition
|
|
std::vector<IColumn *> columns(block.columns());
|
|
for (const auto i : ext::range(0, columns.size()))
|
|
columns[i] = block.getByPosition(i).column.get();
|
|
|
|
std::size_t num_rows = 0;
|
|
while (iterator != result.end())
|
|
{
|
|
Poco::Data::Row & row = *iterator;
|
|
|
|
for (const auto idx : ext::range(0, row.fieldCount()))
|
|
{
|
|
const Poco::Dynamic::Var & value = row[idx];
|
|
|
|
if (!value.isEmpty())
|
|
insertValue(columns[idx], description.types[idx], value);
|
|
else
|
|
insertDefaultValue(columns[idx], *description.sample_columns[idx]);
|
|
}
|
|
|
|
++num_rows;
|
|
if (num_rows == max_block_size)
|
|
break;
|
|
|
|
++iterator;
|
|
}
|
|
|
|
return block;
|
|
}
|
|
|
|
static void insertValue(IColumn * const column, const value_type_t type, const Poco::Dynamic::Var & value)
|
|
{
|
|
switch (type)
|
|
{
|
|
case value_type_t::UInt8: static_cast<ColumnUInt8 *>(column)->insert(value.convert<UInt64>()); break;
|
|
case value_type_t::UInt16: static_cast<ColumnUInt16 *>(column)->insert(value.convert<UInt64>()); break;
|
|
case value_type_t::UInt32: static_cast<ColumnUInt32 *>(column)->insert(value.convert<UInt64>()); break;
|
|
case value_type_t::UInt64: static_cast<ColumnUInt64 *>(column)->insert(value.convert<UInt64>()); break;
|
|
case value_type_t::Int8: static_cast<ColumnInt8 *>(column)->insert(value.convert<Int64>()); break;
|
|
case value_type_t::Int16: static_cast<ColumnInt16 *>(column)->insert(value.convert<Int64>()); break;
|
|
case value_type_t::Int32: static_cast<ColumnInt32 *>(column)->insert(value.convert<Int64>()); break;
|
|
case value_type_t::Int64: static_cast<ColumnInt64 *>(column)->insert(value.convert<Int64>()); break;
|
|
case value_type_t::Float32: static_cast<ColumnFloat32 *>(column)->insert(value.convert<Float64>()); break;
|
|
case value_type_t::Float64: static_cast<ColumnFloat64 *>(column)->insert(value.convert<Float64>()); break;
|
|
case value_type_t::String: static_cast<ColumnString *>(column)->insert(value.convert<String>()); break;
|
|
case value_type_t::Date: static_cast<ColumnUInt16 *>(column)->insert(UInt16{LocalDate{value.convert<String>()}.getDayNum()}); break;
|
|
case value_type_t::DateTime: static_cast<ColumnUInt32 *>(column)->insert(time_t{LocalDateTime{value.convert<String>()}}); break;
|
|
}
|
|
}
|
|
|
|
static void insertDefaultValue(IColumn * const column, const IColumn & sample_column)
|
|
{
|
|
column->insertFrom(sample_column, 0);
|
|
}
|
|
|
|
Poco::Data::Session session;
|
|
Poco::Data::Statement statement;
|
|
Poco::Data::RecordSet result;
|
|
Poco::Data::RecordSet::Iterator iterator;
|
|
|
|
const std::size_t max_block_size;
|
|
ExternalResultDescription description;
|
|
};
|
|
|
|
}
|