From: Vladislav Shpilevoy <v.shpilevoy@tarantool.org> To: "n.pettik" <korablev@tarantool.org>, tarantool-patches@freelists.org Subject: [tarantool-patches] Re: [PATCH v2 1/5] sql: introduce structs assembling DDL arguments during parsing Date: Wed, 27 Mar 2019 17:03:42 +0300 [thread overview] Message-ID: <6b72e8ff-ff1c-2cc7-ced0-1811df66b3dd@tarantool.org> (raw) In-Reply-To: <1B451F1D-39CE-410E-8EAE-55D2DB822C49@tarantool.org> On 27/03/2019 16:44, n.pettik wrote: > >> On 27 Mar 2019, at 16:29, Vladislav Shpilevoy <v.shpilevoy@tarantool.org> wrote: >> On 27/03/2019 16:00, n.pettik wrote: >>> >>>> On 26 Mar 2019, at 21:06, Vladislav Shpilevoy <v.shpilevoy@tarantool.org> wrote: >>>> >>>> Thanks for the fixes! This commit LGTM. >>>> Lets proceed to the next patches, and start >>>> with a rebase, which is going to be hard. >>> >>> Ok. Then I would like to clarify some details to avoid wasting time. >>> In previous patch version, I used next (reworked) grammar to add >>> FK constraints using ALTER: >>> >>> cmd ::= alter_table_start alter_table_action . >>> >>> alter_table_start ::= ALTER TABLE fullname(Z) . (1) >>> >>> alter_table_action ::= add_constraint_def. >>> alter_table_action ::= drop_constraint_def. >>> alter_table_action ::= rename. >>> >>> add_constraint_def ::= add_constraint_start constraint_def. >>> >>> add_constraint_start(N) ::= ADD CONSTRAINT nm(Z). (2) >>> constraint_def ::= foreign_key_def. >>> >>> foreign_key_def ::= FOREIGN KEY LP eidlist(FA) RP REFERENCES nm(T) >>> eidlist_opt(TA) matcharg(M) refargs(R) defer_subclause_opt(D). >>> >>> Now obviously I can’t use it since foreign_key_def should call >>> create_fk_def_init() which in turn requires table name and name >>> of constraint defined in rules (1) and (2). >>> >>> Why I want to use grammar mentioned above: it allows to remove >>> code duplication. Rules to parse constraints are defined three times: >>> >>> 1. ccons rule - that is part of column definition: …, a INT REFERENCES t1); >>> 2. tcons rule - that is part of CREATE TABLE: …, CONSTRAINT c FOREIGN KEY …); >>> 3. ALTER TABLE statement >>> >>> All of them use the same grammar to parse statement starting from >>> REFERENCES keyword. The same applies to UNIQUE and CHECK >>> constraints. >>> >>> IDK how to avoid using alter_entity_def_init() and create_constraint_def_init() >>> and at the same time divide constraint definition into several stages. >>> >>> Ofc, we can still use simple approach like: >>> >>> cmd ::= ALTER TABLE fullname(Z) ADD CONSTRAINT nm(Z) FOREIGN KEY >>> LP eidlist(FA) RP REFERENCES nm(T) eidlist_opt(TA) matcharg(M) >>> refargs(R) defer_subclause_opt(D) >>> >>> cmd ::= ALTER TABLE fullname(Z) ADD CONSTRAINT nm(Z) UNIQUE >>> LP sortlist(X) RP >>> >>> cmd ::= ALTER TABLE fullname(Z) ADD CONSTRAINT nm(Z) PRIMARY KEY >>> LP sortlist(X) RP >>> >>> cmd ::= ALTER TABLE fullname(Z) ADD CONSTRAINT nm(Z) CHECK … >>> >>> cmd ::= ALTER TABLE fullname(Z) RENAME TO nm(N) . >>> >>> Is this OK? >>> >> >> Obviously, it is not. Why can't you define this? >> >> alter_table_start(T) ::= ALTER TABLE fullname(T) >> alter_add_constraint(T, N) ::= alter_table_start(T) ADD CONSTRAINT nm(N). > > Lemon can’t use two aliases as rule parameters at the same time. > Instead we can introduce *another one* local struct to hold these names. Yes, you can define a structure in parse.y to store these two parameters, and unpack it back inside the concrete rules. It means, that such a helper struct will never be stored anywhere out of parse.y. > Anyway my initial worry was not about duplication of ALTER TABLE CREATE CONSTRAINT, > but rather of constraints grammar (i.e. starting from FOREIGN KEY…). For constraints grammar you can consult the standard. I do not remember how it defines FOREIGN KEY rules, if it does at all. Personally for me it looks ok. > >> cmd ::= alter_add_constraint(T, N) FOREIGN KEY ... >> cmd ::= alter_add_constraint(T, N) UNIQUE LP sortlist(X) RP >> cmd ::= alter_add_constraint(T, N) PRIMARY KEY LP sortlist(X) RP >> cmd ::= alter_add_constraint(T, N) CHECK ... >> cmd ::= alter_table_start RENAME TO nm(N) . >> >> Then inside each cmd you have both table and constraint names. >
next prev parent reply other threads:[~2019-03-27 14:03 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-01-23 17:56 [tarantool-patches] [PATCH v2 0/5] Introduce ALTER TABLE ADD CONSTRAINT UNIQUE/PK Nikita Pettik 2019-01-23 17:56 ` [tarantool-patches] [PATCH v2 1/5] sql: introduce structs assembling DDL arguments during parsing Nikita Pettik 2019-01-24 8:36 ` [tarantool-patches] " Konstantin Osipov 2019-01-24 10:47 ` n.pettik 2019-01-24 12:30 ` Konstantin Osipov 2019-01-29 19:03 ` n.pettik 2019-01-29 19:29 ` Vladislav Shpilevoy 2019-01-29 20:04 ` n.pettik 2019-01-29 20:20 ` Vladislav Shpilevoy 2019-01-29 21:25 ` n.pettik 2019-01-31 19:32 ` n.pettik 2019-02-04 15:25 ` Vladislav Shpilevoy 2019-02-08 14:25 ` n.pettik 2019-02-15 20:13 ` Vladislav Shpilevoy 2019-02-27 22:56 ` n.pettik 2019-03-12 12:50 ` Vladislav Shpilevoy 2019-03-14 18:13 ` n.pettik 2019-03-25 11:25 ` Vladislav Shpilevoy 2019-03-26 18:01 ` n.pettik 2019-03-26 18:06 ` Vladislav Shpilevoy 2019-03-27 13:00 ` n.pettik 2019-03-27 13:29 ` Vladislav Shpilevoy 2019-03-27 13:44 ` n.pettik 2019-03-27 14:03 ` Vladislav Shpilevoy [this message] 2019-03-27 14:11 ` n.pettik 2019-01-23 17:56 ` [tarantool-patches] [PATCH v2 2/5] sql: rework ALTER TABLE grammar Nikita Pettik 2019-01-23 17:56 ` [tarantool-patches] [PATCH v2 3/5] sql: refactor getNewIid() function Nikita Pettik 2019-01-23 17:56 ` [tarantool-patches] [PATCH v2 4/5] sql: fix error message for improperly created index Nikita Pettik 2019-02-08 17:14 ` [tarantool-patches] " Konstantin Osipov 2019-01-23 17:56 ` [tarantool-patches] [PATCH v2 5/5] sql: introduce ALTER TABLE ADD CONSTRAINT UNIQUE/PRIMARY KEY Nikita Pettik 2019-01-24 8:31 ` [tarantool-patches] " Konstantin Osipov 2019-01-29 19:29 ` Vladislav Shpilevoy 2019-02-08 17:16 ` Konstantin Osipov 2019-02-08 17:36 ` n.pettik
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