ClickHouse/dbms/src/Dictionaries/ODBCDictionarySource.cpp

#include <DB/Dictionaries/ODBCDictionarySource.h>


namespace DB
{


decltype(ODBCDictionarySource::max_block_size) ODBCDictionarySource::max_block_size;


ODBCDictionarySource::ODBCDictionarySource(const DictionaryStructure & dict_struct_,
	const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix,
	const Block & sample_block)
	: dict_struct{dict_struct_},
	  db{config.getString(config_prefix + ".db", "")},
	  table{config.getString(config_prefix + ".table")},
	  where{config.getString(config_prefix + ".where", "")},
	  sample_block{sample_block},
	  pool{std::make_shared<Poco::Data::SessionPool>(
		  config.getString(config_prefix + ".connector", "ODBC"),
		  config.getString(config_prefix + ".connection_string"))},
	  query_builder{dict_struct, db, table, where},
	  load_all_query{query_builder.composeLoadAllQuery()}
{
}

/// copy-constructor is provided in order to support cloneability
ODBCDictionarySource::ODBCDictionarySource(const ODBCDictionarySource & other)
	: dict_struct{other.dict_struct},
	  db{other.db},
	  table{other.table},
	  where{other.where},
	  sample_block{other.sample_block},
	  pool{other.pool},
	  query_builder{dict_struct, db, table, where},
	  load_all_query{other.load_all_query}
{
}

BlockInputStreamPtr ODBCDictionarySource::loadAll()
{
	LOG_TRACE(log, load_all_query);
	return std::make_shared<ODBCBlockInputStream>(pool->get(), load_all_query, sample_block, max_block_size);
}

BlockInputStreamPtr ODBCDictionarySource::loadIds(const std::vector<std::uint64_t> & ids)
{
	const auto query = query_builder.composeLoadIdsQuery(ids);
	return std::make_shared<ODBCBlockInputStream>(pool->get(), query, sample_block, max_block_size);
}

BlockInputStreamPtr ODBCDictionarySource::loadKeys(
	const ConstColumnPlainPtrs & key_columns, const std::vector<std::size_t> & requested_rows)
{
	const auto query = query_builder.composeLoadKeysQuery(key_columns, requested_rows, ExternalQueryBuilder::AND_OR_CHAIN);
	return std::make_shared<ODBCBlockInputStream>(pool->get(), query, sample_block, max_block_size);
}

bool ODBCDictionarySource::isModified() const
{
	return true;
}

bool ODBCDictionarySource::supportsSelectiveLoad() const
{
	return true;
}

DictionarySourcePtr ODBCDictionarySource::clone() const
{
	return std::make_unique<ODBCDictionarySource>(*this);
}

std::string ODBCDictionarySource::toString() const
{
	return "ODBC: " + db + '.' + table + (where.empty() ? "" : ", where: " + where);
}


}