Method processQuery

src/Server/PostgreSQLHandler.cpp:269–320

}

void PostgreSQLHandler::processQuery()
{
    try
    {
        std::unique_ptr<PostgreSQLProtocol::Messaging::Query> query =
            message_transport->receive<PostgreSQLProtocol::Messaging::Query>();

        if (isEmptyQuery(query->query))
        {
            message_transport->send(PostgreSQLProtocol::Messaging::EmptyQueryResponse());
            return;
        }

        bool psycopg2_cond = query->query == "BEGIN" || query->query == "COMMIT"; // psycopg2 starts and ends queries with BEGIN/COMMIT commands
        bool jdbc_cond = query->query.find("SET extra_float_digits") != String::npos || query->query.find("SET application_name") != String::npos; // jdbc starts with setting this parameter
        if (psycopg2_cond || jdbc_cond)
        {
            message_transport->send(
                PostgreSQLProtocol::Messaging::CommandComplete(
                    PostgreSQLProtocol::Messaging::CommandComplete::classifyQuery(query->query), 0));
            return;
        }

        const auto & settings = connection_context->getSettingsRef();
        std::vector<String> queries;
        auto parse_res = splitMultipartQuery(
            query->query, queries, settings.max_query_size, settings.max_parser_depth, ParserSettings::valueOf(settings));
        if (!parse_res.second)
            throw Exception("Cannot parse and execute the following part of query: " + String(parse_res.first), ErrorCodes::SYNTAX_ERROR);

        for (const auto & spl_query : queries)
        {
            /// FIXME why do we execute all queries in a single connection context?
            CurrentThread::QueryScope query_scope{connection_context};
            ReadBufferFromString read_buf(spl_query);
            executeQuery(read_buf, *out, false, connection_context, {});

            PostgreSQLProtocol::Messaging::CommandComplete::Command command =
                PostgreSQLProtocol::Messaging::CommandComplete::classifyQuery(spl_query);
            message_transport->send(PostgreSQLProtocol::Messaging::CommandComplete(command, 0), true);
        }

    }
    catch (const Exception & e)
    {
        message_transport->send(
            PostgreSQLProtocol::Messaging::ErrorOrNoticeResponse(
                PostgreSQLProtocol::Messaging::ErrorOrNoticeResponse::ERROR, "2F000", "Query execution failed.\n" + e.displayText()),
            true);
        throw;
    }
}

bool PostgreSQLHandler::isEmptyQuery(const String & query)
{