Function registerDatabaseFilesystem

src/Databases/DatabaseFilesystem.cpp:245–275

void registerDatabaseFilesystem(DatabaseFactory & factory);
void registerDatabaseFilesystem(DatabaseFactory & factory)
{
    auto create_fn = [](const DatabaseFactory::Arguments & args)
    {
        auto * engine_define = args.create_query.storage;
        const ASTFunction * engine = engine_define->engine;
        const String & engine_name = engine_define->engine->name;

        /// If init_path is empty, then the current path will be used
        std::string init_path;

        if (engine->arguments && !engine->arguments->children.empty())
        {
            if (engine->arguments->children.size() != 1)
                throw Exception(ErrorCodes::BAD_ARGUMENTS, "Filesystem database requires at most 1 argument: filesystem_path");

            const auto & arguments = engine->arguments->children;
            init_path = safeGetLiteralValue<String>(arguments[0], engine_name);
        }

        return std::make_shared<DatabaseFilesystem>(args.database_name, init_path, args.context);
    };
    factory.registerDatabase("Filesystem", create_fn, {
        .supports_arguments = true,
        .is_external = true,
        .source_access_type = AccessTypeObjects::Source::FILE,
    }, Documentation{
        .description = "A read-only database that exposes files in a directory on the local filesystem as tables, queryable by their path.",
        .syntax = "ENGINE = Filesystem([path])",
        .related = {"S3", "HDFS"}});
}
}