From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 1BF902161F for ; Thu, 18 Jul 2019 16:16:57 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 09YpAsUxjgNn for ; Thu, 18 Jul 2019 16:16:57 -0400 (EDT) Received: from smtp39.i.mail.ru (smtp39.i.mail.ru [94.100.177.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTPS id D14AE212E9 for ; Thu, 18 Jul 2019 16:16:56 -0400 (EDT) Subject: [tarantool-patches] Re: [PATCH 6/6] sql: allow to specify UNSIGNED column type References: <734EC309-6DCF-42C2-8041-135A8B68E935@tarantool.org> <9a397d31-1cae-0dd0-cdd6-733388cb01af@tarantool.org> <552F96C1-DAC5-4F18-9F5A-BF50C6BBC205@tarantool.org> From: Vladislav Shpilevoy Message-ID: <8e4feefd-7bfb-18af-fd0f-b45384e5d2ef@tarantool.org> Date: Thu, 18 Jul 2019 22:18:36 +0200 MIME-Version: 1.0 In-Reply-To: <552F96C1-DAC5-4F18-9F5A-BF50C6BBC205@tarantool.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: tarantool-patches-bounce@freelists.org Errors-to: tarantool-patches-bounce@freelists.org Reply-To: tarantool-patches@freelists.org List-Help: List-Unsubscribe: List-software: Ecartis version 1.0.0 List-Id: tarantool-patches List-Subscribe: List-Owner: List-post: List-Archive: To: "n.pettik" , tarantool-patches@freelists.org Hi! Thanks for the fixes! >> ------------------------- >> vdbe.c:307 >> >>> case FIELD_TYPE_INTEGER: >>> case FIELD_TYPE_UNSIGNED: >>> if ((record->flags & MEM_Int) == MEM_Int) >>> return 0; >>> if ((record->flags & MEM_UInt) == MEM_UInt) >>> return 0; >>> if ((record->flags & MEM_Real) == MEM_Real) { >>> int64_t i = (int64_t) record->u.r; >>> if (i == record->u.r) >>> mem_set_int(record, record->u.r, >>> record->u.r <= -1); >>> return 0; >>> } >> >> It is a part of function mem_apply_type. When target type is >> UNSIGNED, and a value is MEM_Int, you do nothing. Why? Looks like >> it is possible to pass here a negative value, and CAST UNSIGNED >> would do nothing. > > Basically, this function implements sort of implicit cast > which takes place before comparison/assignment. > For comparisons it makes no sense - we can compare > integer with unsigned value - the latter is always greater. > For assignment it is also meaningless: if we attempt > at inserting negative values to unsigned field appropriate > error will be raised anyway. If you can come up with > specific example, let’s discuss it. > I can't provide a test. But the function is named mem_apply_type, and it doesn't apply type, when it is unsigned, and a value is negative. Doesn't it look wrong to you? If some code wants to get an integer, it can apply FIELD_TYPE_INTEGER instead of FIELD_TYPE_UNSIGNED. IMO, an attempt to apply unsigned to int should raise an error here. Otherwise this function can't be named 'apply_type' because it ignores negative -> unsigned case.