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 C67D424661 for ; Thu, 18 Jul 2019 17:06:58 -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 5hEuG9VxocsG for ; Thu, 18 Jul 2019 17:06:58 -0400 (EDT) Received: from smtp51.i.mail.ru (smtp51.i.mail.ru [94.100.177.111]) (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 7AC4D216B7 for ; Thu, 18 Jul 2019 17:06:58 -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> <8e4feefd-7bfb-18af-fd0f-b45384e5d2ef@tarantool.org> <127420CE-540E-439C-B2BD-20007EE98328@tarantool.org> From: Vladislav Shpilevoy Message-ID: <989f9710-043f-447a-0cc4-76eb317bc1e9@tarantool.org> Date: Thu, 18 Jul 2019 23:08:35 +0200 MIME-Version: 1.0 In-Reply-To: <127420CE-540E-439C-B2BD-20007EE98328@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 On 18/07/2019 22:56, n.pettik wrote: > > >> On 18 Jul 2019, at 23:18, Vladislav Shpilevoy > wrote: >> >> 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. > > Okay, let’s rename it. I can suggest these options: > > mem_cast_implicit() > mem_cast_implicit_to_type() > mem_implicit_cast_to_type() > mem_convert_implicit() > mem_convert_to_type() > mem_type_coerce_implicit() > mem_type_implicit_coercion() > mem_type_coercion_implicit() > mem_implicit_type_juggling() > mem_implicit_juggle_to_type() > mem_do_implicit_conversion() > mem_do_implicit_coercion() > > Or any other combination :) > But it is not implicit. It just does not work, when a value is negative, and type is unsigned.