mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-23 16:12:01 +00:00
122 lines
4.0 KiB
C++
122 lines
4.0 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 <ext/range.hpp>
|
|
#include <mysqlxx/Query.h>
|
|
#include <mysqlxx/PoolWithFailover.h>
|
|
#include <vector>
|
|
#include <string>
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int NUMBER_OF_COLUMNS_DOESNT_MATCH;
|
|
}
|
|
|
|
/// Allows processing results of a MySQL query as a sequence of Blocks, simplifies chaining
|
|
class MySQLBlockInputStream final : public IProfilingBlockInputStream
|
|
{
|
|
public:
|
|
MySQLBlockInputStream(
|
|
const mysqlxx::PoolWithFailover::Entry & entry, const std::string & query_str, const Block & sample_block,
|
|
const std::size_t max_block_size)
|
|
: entry{entry}, query{this->entry->query(query_str)}, result{query.use()},
|
|
max_block_size{max_block_size}
|
|
{
|
|
if (sample_block.columns() != result.getNumFields())
|
|
throw Exception{
|
|
"mysqlxx::UseQueryResult contains " + toString(result.getNumFields()) + " columns while " +
|
|
toString(sample_block.columns()) + " expected",
|
|
ErrorCodes::NUMBER_OF_COLUMNS_DOESNT_MATCH};
|
|
|
|
description.init(sample_block);
|
|
}
|
|
|
|
String getName() const override { return "MySQL"; }
|
|
|
|
String getID() const override
|
|
{
|
|
return "MySQL(" + query.str() + ")";
|
|
}
|
|
|
|
private:
|
|
using ValueType = ExternalResultDescription::ValueType;
|
|
|
|
Block readImpl() override
|
|
{
|
|
auto row = result.fetch();
|
|
if (!row)
|
|
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 (row)
|
|
{
|
|
for (const auto idx : ext::range(0, row.size()))
|
|
{
|
|
const auto value = row[idx];
|
|
if (!value.isNull())
|
|
insertValue(columns[idx], description.types[idx], value);
|
|
else
|
|
insertDefaultValue(columns[idx], *description.sample_columns[idx]);
|
|
}
|
|
|
|
++num_rows;
|
|
if (num_rows == max_block_size)
|
|
break;
|
|
|
|
row = result.fetch();
|
|
}
|
|
|
|
return block;
|
|
}
|
|
|
|
static void insertValue(IColumn * const column, const ValueType type, const mysqlxx::Value & value)
|
|
{
|
|
switch (type)
|
|
{
|
|
case ValueType::UInt8: static_cast<ColumnUInt8 *>(column)->insert(value.getUInt()); break;
|
|
case ValueType::UInt16: static_cast<ColumnUInt16 *>(column)->insert(value.getUInt()); break;
|
|
case ValueType::UInt32: static_cast<ColumnUInt32 *>(column)->insert(value.getUInt()); break;
|
|
case ValueType::UInt64: static_cast<ColumnUInt64 *>(column)->insert(value.getUInt()); break;
|
|
case ValueType::Int8: static_cast<ColumnInt8 *>(column)->insert(value.getInt()); break;
|
|
case ValueType::Int16: static_cast<ColumnInt16 *>(column)->insert(value.getInt()); break;
|
|
case ValueType::Int32: static_cast<ColumnInt32 *>(column)->insert(value.getInt()); break;
|
|
case ValueType::Int64: static_cast<ColumnInt64 *>(column)->insert(value.getInt()); break;
|
|
case ValueType::Float32: static_cast<ColumnFloat32 *>(column)->insert(value.getDouble()); break;
|
|
case ValueType::Float64: static_cast<ColumnFloat64 *>(column)->insert(value.getDouble()); break;
|
|
case ValueType::String: static_cast<ColumnString *>(column)->insertData(value.data(), value.size()); break;
|
|
case ValueType::Date: static_cast<ColumnUInt16 *>(column)->insert(UInt16{value.getDate().getDayNum()}); break;
|
|
case ValueType::DateTime: static_cast<ColumnUInt32 *>(column)->insert(time_t{value.getDateTime()}); break;
|
|
}
|
|
}
|
|
|
|
static void insertDefaultValue(IColumn * const column, const IColumn & sample_column)
|
|
{
|
|
column->insertFrom(sample_column, 0);
|
|
}
|
|
|
|
mysqlxx::PoolWithFailover::Entry entry;
|
|
mysqlxx::Query query;
|
|
mysqlxx::UseQueryResult result;
|
|
const std::size_t max_block_size;
|
|
ExternalResultDescription description;
|
|
};
|
|
|
|
}
|