Method fuzzCreateQuery

src/Common/QueryFuzzer.cpp:904–1321

}

void QueryFuzzer::fuzzCreateQuery(ASTCreateQuery & create)
{
    if (create.columns_list && create.columns_list->columns)
    {
        for (auto & ast : create.columns_list->columns->children)
        {
            if (auto * column = ast->as<ASTColumnDeclaration>())
            {
                fuzzColumnDeclaration(*column);
                fuzz(ast);
            }
        }
    }

    if (create.columns_list && create.columns_list->indices)
    {
        for (auto & ast : create.columns_list->indices->children)
        {
            if (auto * index = ast->as<ASTIndexDeclaration>())
                fuzzIndexDeclaration(*index);
        }
    }

    if (create.storage && create.storage->engine)
    {
        auto & engine_name = create.storage->engine->name;

        if (create.database && !create.table)
        {
            /// For database engine fuzzing, only swap between parameter-free engines.
            /// Avoid touching Replicated (needs ZooKeeper), Lazy (needs arg), or external
            /// engines (MySQL/PostgreSQL need connection params).
            static const std::unordered_set<String> safe_database_engines = {"Atomic", "Memory", "Dictionary"};
            if (safe_database_engines.contains(engine_name) && fuzz_rand() % 10 == 0)
            {
                engine_name = pickRandomly(fuzz_rand, safe_database_engines);
                if (auto & arguments = create.storage->engine->arguments)
                    arguments->children.clear();
            }
        }
        else
        {
            /// Replace ReplicatedMergeTree to ordinary MergeTree
            /// to avoid inconsistency of metadata in zookeeper.
            if (startsWith(engine_name, "Replicated"))
            {
                engine_name = engine_name.substr(strlen("Replicated"));
                auto * engine = create.storage->engine;
                if (engine->arguments)
                {
                    if (engine->arguments->children.size() <= 2)
                        engine->reset(engine->arguments);
                    else
                        engine->arguments->children.erase(engine->arguments->children.begin(), engine->arguments->children.begin() + 2);
                }
            }

            /// Swap between MergeTree variants that require no mandatory extra columns.