Method getLeftTableStorage

src/Interpreters/JoinedTables.cpp:216–259

}

StoragePtr JoinedTables::getLeftTableStorage()
{
    if (isLeftTableSubquery())
        return {};

    if (isLeftTableFunction())
    {
        /// For parameterized views in refreshable materialized views, use the current context's database
        /// instead of the query context's database. This ensures unqualified parameterized view
        /// references resolve in the correct database (MV's database, not session's database).
        auto table_function_context = context->getQueryContext();
        if (is_create_parameterized_view)
        {
            /// Temporarily set the current database to match the context we're analyzing in
            table_function_context = Context::createCopy(table_function_context);
            table_function_context->setCurrentDatabase(context->getCurrentDatabase());
        }
        return table_function_context->executeTableFunction(left_table_expression, &select_query);
    }

    StorageID table_id = StorageID::createEmpty();
    if (left_db_and_table)
    {
        table_id = context->resolveStorageID(StorageID(left_db_and_table->database, left_db_and_table->table, left_db_and_table->uuid));
    }
    else /// If the table is not specified - use the table `system.one`.
    {
        table_id = StorageID("system", "one");
    }

    if (auto view_source = context->getViewSource())
    {
        const auto & storage_values = static_cast<const StorageValues &>(*view_source);
        auto tmp_table_id = storage_values.getStorageID();
        if (tmp_table_id.database_name == table_id.database_name && tmp_table_id.table_name == table_id.table_name)
        {
            /// Read from view source.
            return context->getViewSource();
        }
    }

    /// Read from table. Even without table expression (implicit SELECT ... FROM system.one).
    return DatabaseCatalog::instance().getTable(table_id, context);
}

bool JoinedTables::resolveTables()
{