Method loadWarningMessages

programs/client/Client.cpp:149–203

Make query to get all server warnings

/// Make query to get all server warnings
std::vector<String> Client::loadWarningMessages()
{
    /// Older server versions cannot execute the query loading warnings.
    constexpr UInt64 min_server_revision_to_load_warnings = DBMS_MIN_PROTOCOL_VERSION_WITH_VIEW_IF_PERMITTED;

    if (server_revision < min_server_revision_to_load_warnings)
        return {};

    std::vector<String> messages;
    connection->sendQuery(connection_parameters.timeouts,
                          "SELECT * FROM viewIfPermitted(SELECT message FROM system.warnings ELSE null('message String'))",
                          {} /* query_parameters */,
                          "" /* query_id */,
                          QueryProcessingStage::Complete,
                          &client_context->getSettingsRef(),
                          &client_context->getClientInfo(), false, {}, {});
    while (true)
    {
        Packet packet = connection->receivePacket();
        switch (packet.type)
        {
            case Protocol::Server::Data:
                if (!packet.block.empty())
                {
                    const ColumnString & column = typeid_cast<const ColumnString &>(*packet.block.getByPosition(0).column);

                    size_t rows = packet.block.rows();
                    for (size_t i = 0; i < rows; ++i)
                        messages.emplace_back(column[i].safeGet<String>());
                }
                continue;

            case Protocol::Server::Progress:
            case Protocol::Server::ProfileInfo:
            case Protocol::Server::Totals:
            case Protocol::Server::Extremes:
            case Protocol::Server::Log:
                continue;

            case Protocol::Server::Exception:
                packet.exception->rethrow();
                return messages;

            case Protocol::Server::EndOfStream:
                return messages;

            case Protocol::Server::ProfileEvents:
                continue;

            default:
                throw Exception(
                    ErrorCodes::UNKNOWN_PACKET_FROM_SERVER, "Unknown packet {} from server {}", packet.type, connection->getDescription());
        }
    }
}


Poco::Util::LayeredConfiguration & Client::getClientConfiguration()