From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpng3.m.smailru.net (smtpng3.m.smailru.net [94.100.177.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id A5DAA46970E for ; Mon, 13 Jan 2020 15:58:30 +0300 (MSK) Date: Mon, 13 Jan 2020 15:58:29 +0300 From: Nikita Pettik Message-ID: <20200113125829.GB7851@tarantool.org> References: <55e18164c96a568a757423df813dc4e73f45b1c9.1577782147.git.imeevma@gmail.com> <20191231085607.GB30188@tarantool.org> <20191231094611.GA9514@tarantool.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191231094611.GA9514@tarantool.org> Subject: Re: [Tarantool-patches] [PATCH v2 1/1] sql: make NUMBER to be union of SQL numeric types List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mergen Imeev Cc: tarantool-patches@dev.tarantool.org On 31 Dec 12:46, Mergen Imeev wrote: > Hi! Thank you for review. My answer below. > > On Tue, Dec 31, 2019 at 10:56:07AM +0200, Nikita Pettik wrote: > > On 31 Dec 11:50, imeevma@tarantool.org wrote: > > > This patch makes number to be union of UNSIGNED, INTEGER and > > > DOUBLE numeric types. > > > > > > Closes #4233 > > > Closes #4463 > > > > Please, explain in details changes in explicit/implicit > > casts behaviour. > > > Fixed: > > commit 492646da4f781b863e5e3e488a0be53f31d28964 > Author: Mergen Imeev > Date: Sat Oct 26 17:27:53 2019 +0300 > > sql: make NUMBER to be union of SQL numeric types > > This patch makes number to be union of UNSIGNED, INTEGER and > DOUBLE numeric types. > > Closes #4233 > Closes #4463 > > @TarantoolBot document > Title: NUMBER type in SQL. Could you please intead of 3 paragraphs just include following changelog list: "This patch makes definition of NUMBER type be consistent with NoSQL. Previously (for historic reasons) in half-cases NUMBER served as a synonym of DOUBLE type. After patch is applied following will change: - CAST AS NUMBER operation no more longer results in any value change in case value is already of numeric type. Example: Obsolete behaviour: SELECT CAST(922337206854774800 AS NUMBER); Result: 9223372036854774784 New behaviour: SELECT CAST(922337206854774800 AS NUMBER); Result: 9223372036854774800LL - ... " Or group implicit/explicit cast changes. Text below is quite compicated to perceive (IMHO). > > The NUMBER type in SQL is the union of all currently available > numeric types in SQL: INTEGER, UNSIGNED, and DOUBLE. The types > INTEGER and DOUBLE can be called subtypes of type NUMBER. Any > value of type NUMBER has a subtype of INTEGER or DOUBLE. When > any numeric value is implicitly or explicitly casted to NUMBER, > the only thing that can change is its type. Its type will become > NUMBER. When a value of type NUMBER is cast explicitly or > implicitly to other numeric types, the rules applicable to the > cast are determined by the subtype of the value. > > If a value of type STRING can be implicitly cast to value of > type INTEGER or DOUBLE, then this value can be cast explicitly > and implicitly to a value of type NUMBER. If this value can be > implicitly cast to INTEGER, then its subtype will be INTEGER. > The subtype will be DOUBLE in another case. > > If a value of type VARBINARY can be explicitly cast to type > INTEGER or DOUBLE, then this value can be explicitly cast to a > value of type NUMBER. If this value can be explicitly cast to > INTEGER, then its subtype will be INTEGER. The subtype will be > DOUBLE in another case. > > > ---