C++ DatabasePtr::createTable方法代码示例

BlockIO InterpreterCreateQuery::createTable(ASTCreateQuery & create)
{
    if (!create.cluster.empty())
    {
        NameSet databases{create.database};
        if (!create.to_table.empty())
            databases.emplace(create.to_database);

        return executeDDLQueryOnCluster(query_ptr, context, std::move(databases));
    }

    String path = context.getPath();
    String current_database = context.getCurrentDatabase();

    String database_name = create.database.empty() ? current_database : create.database;
    String table_name = create.table;
    String table_name_escaped = escapeForFileName(table_name);

    // If this is a stub ATTACH query, read the query definition from the database
    if (create.attach && !create.storage && !create.columns)
    {
        // Table SQL definition is available even if the table is detached
        auto query = context.getCreateTableQuery(database_name, table_name);
        auto & as_create = typeid_cast<const ASTCreateQuery &>(*query);
        create = as_create; // Copy the saved create query, but use ATTACH instead of CREATE
        create.attach = true;
    }

    if (create.to_database.empty())
        create.to_database = current_database;

    if (create.select && (create.is_view || create.is_materialized_view))
    {
        AddDefaultDatabaseVisitor visitor(current_database);
        visitor.visit(*create.select);
    }

    Block as_select_sample;
    if (create.select && (!create.attach || !create.columns))
        as_select_sample = InterpreterSelectWithUnionQuery::getSampleBlock(create.select->clone(), context);

    String as_database_name = create.as_database.empty() ? current_database : create.as_database;
    String as_table_name = create.as_table;

    StoragePtr as_storage;
    TableStructureReadLockPtr as_storage_lock;
    if (!as_table_name.empty())
    {
        as_storage = context.getTable(as_database_name, as_table_name);
        as_storage_lock = as_storage->lockStructure(false);
    }

    /// Set and retrieve list of columns.
    ColumnsDescription columns = setColumns(create, as_select_sample, as_storage);

    /// Some column types may be not allowed according to settings.
    if (!create.attach)
        checkSupportedTypes(columns, context);

    /// Set the table engine if it was not specified explicitly.
    setEngine(create);

    StoragePtr res;

    {
        std::unique_ptr<DDLGuard> guard;

        String data_path;
        DatabasePtr database;

        if (!create.temporary)
        {
            database = context.getDatabase(database_name);
            data_path = database->getDataPath();

            /** If the request specifies IF NOT EXISTS, we allow concurrent CREATE queries (which do nothing).
              * If table doesnt exist, one thread is creating table, while others wait in DDLGuard.
              */
            guard = context.getDDLGuard(database_name, table_name);

            /// Table can be created before or it can be created concurrently in another thread, while we were waiting in DDLGuard.
            if (database->isTableExist(context, table_name))
            {
                if (create.if_not_exists)
                    return {};
                else
                    throw Exception("Table " + database_name + "." + table_name + " already exists.", ErrorCodes::TABLE_ALREADY_EXISTS);
            }
        }
        else if (context.tryGetExternalTable(table_name) && create.if_not_exists)
             return {};

        res = StorageFactory::instance().get(create,
            data_path,
            table_name,
            database_name,
            context,
            context.getGlobalContext(),
            columns,
            create.attach,
//.........这里部分代码省略.........

BlockIO InterpreterCreateQuery::createTable(ASTCreateQuery & create)
{
    if (!create.cluster.empty())
    {
        NameSet databases{create.database};
        if (!create.to_table.empty())
            databases.emplace(create.to_database);

        return executeDDLQueryOnCluster(query_ptr, context, databases);
    }

    String path = context.getPath();
    String current_database = context.getCurrentDatabase();

    String database_name = create.database.empty() ? current_database : create.database;
    String table_name = create.table;
    String table_name_escaped = escapeForFileName(table_name);

    // If this is a stub ATTACH query, read the query definition from the database
    if (create.attach && !create.storage && !create.columns)
    {
        // Table SQL definition is available even if the table is detached
        auto query = context.getCreateTableQuery(database_name, table_name);
        auto & as_create = typeid_cast<const ASTCreateQuery &>(*query);
        create = as_create; // Copy the saved create query, but use ATTACH instead of CREATE
        create.attach = true;
    }

    if (create.to_database.empty())
        create.to_database = current_database;

    if (create.select && (create.is_view || create.is_materialized_view))
        create.select->setDatabaseIfNeeded(current_database);

    Block as_select_sample;
    if (create.select && (!create.attach || !create.columns))
        as_select_sample = InterpreterSelectWithUnionQuery::getSampleBlock(create.select->clone(), context);

    String as_database_name = create.as_database.empty() ? current_database : create.as_database;
    String as_table_name = create.as_table;

    StoragePtr as_storage;
    TableStructureReadLockPtr as_storage_lock;
    if (!as_table_name.empty())
    {
        as_storage = context.getTable(as_database_name, as_table_name);
        as_storage_lock = as_storage->lockStructure(false, __PRETTY_FUNCTION__);
    }

    /// Set and retrieve list of columns.
    ColumnsDescription columns = setColumns(create, as_select_sample, as_storage);

    /// Set the table engine if it was not specified explicitly.
    setEngine(create);

    StoragePtr res;

    {
        std::unique_ptr<DDLGuard> guard;

        String data_path;
        DatabasePtr database;

        if (!create.is_temporary)
        {
            database = context.getDatabase(database_name);
            data_path = database->getDataPath();

            /** If the table already exists, and the request specifies IF NOT EXISTS,
              *  then we allow concurrent CREATE queries (which do nothing).
              * Otherwise, concurrent queries for creating a table, if the table does not exist,
              *  can throw an exception, even if IF NOT EXISTS is specified.
              */
            guard = context.getDDLGuardIfTableDoesntExist(database_name, table_name,
                "Table " + database_name + "." + table_name + " is creating or attaching right now");

            if (!guard)
            {
                if (create.if_not_exists)
                    return {};
                else
                    throw Exception("Table " + database_name + "." + table_name + " already exists.", ErrorCodes::TABLE_ALREADY_EXISTS);
            }
        }
        else if (context.tryGetExternalTable(table_name) && create.if_not_exists)
             return {};

        res = StorageFactory::instance().get(create,
            data_path,
            table_name,
            database_name,
            context,
            context.getGlobalContext(),
            columns,
            create.attach,
            false);

        if (create.is_temporary)
            context.getSessionContext().addExternalTable(table_name, res, query_ptr);
        else
//.........这里部分代码省略.........