Function extractPartitionKey

programs/copier/Internals.cpp:99–139

}

ASTPtr extractPartitionKey(const ASTPtr & storage_ast)
{
    String storage_str = queryToString(storage_ast);

    const auto & storage = storage_ast->as<ASTStorage &>();
    const auto & engine = storage.engine->as<ASTFunction &>();

    if (!endsWith(engine.name, "MergeTree"))
    {
        throw Exception(
                "Unsupported engine was specified in " + storage_str + ", only *MergeTree engines are supported",
                ErrorCodes::BAD_ARGUMENTS);
    }

    if (isExtendedDefinitionStorage(storage_ast))
    {
        if (storage.partition_by)
            return storage.partition_by->clone();

        static const char * all = "all";
        return std::make_shared<ASTLiteral>(Field(all, strlen(all)));
    }
    else
    {
        bool is_replicated = startsWith(engine.name, "Replicated");
        size_t min_args = is_replicated ? 3 : 1;

        if (!engine.arguments)
            throw Exception("Expected arguments in " + storage_str, ErrorCodes::BAD_ARGUMENTS);

        ASTPtr arguments_ast = engine.arguments->clone();
        ASTs & arguments = arguments_ast->children;

        if (arguments.size() < min_args)
            throw Exception("Expected at least " + toString(min_args) + " arguments in " + storage_str,
                            ErrorCodes::BAD_ARGUMENTS);

        ASTPtr & month_arg = is_replicated ? arguments[2] : arguments[1];
        return makeASTFunction("toYYYYMM", month_arg->clone());
    }
}

ASTPtr extractPrimaryKey(const ASTPtr & storage_ast)
{