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 AF63824466 for ; Mon, 14 Jan 2019 09:05:52 -0500 (EST) 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 qdB5m6jwddCF for ; Mon, 14 Jan 2019 09:05:52 -0500 (EST) Received: from smtpng2.m.smailru.net (smtpng2.m.smailru.net [94.100.179.3]) (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 69A8623FE7 for ; Mon, 14 Jan 2019 09:05:52 -0500 (EST) Subject: [tarantool-patches] Re: [PATCH 2/6] sql: rework ALTER TABLE grammar References: <0117c011c631182ddd64cff7a46e2b3e940bf03c.1547035183.git.korablev@tarantool.org> From: Vladislav Shpilevoy Message-ID: <65ef264c-c582-3d4d-2f5c-269c75decd98@tarantool.org> Date: Mon, 14 Jan 2019 17:05:43 +0300 MIME-Version: 1.0 In-Reply-To: <0117c011c631182ddd64cff7a46e2b3e940bf03c.1547035183.git.korablev@tarantool.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: tarantool-patches@freelists.org, Nikita Pettik Thanks for the patch! See 5 comments below. On 09/01/2019 15:13, Nikita Pettik wrote: > Since ALTER TABLE ADD CONSTRAINT can be used to add various constraint > types (foreign key, unique etc), we should rework its grammar. 1. But you still can not add a unique constraint via ADD CONSTRAINT ... The reworked grammar can be used for foreign keys only, until the last commit. > As a reference for it lets use one from ANSI. > > Needed for #3097 > --- > src/box/sql/parse.y | 44 +++++++++++++++++++++++++++++--------------- > 1 file changed, 29 insertions(+), 15 deletions(-) > > diff --git a/src/box/sql/parse.y b/src/box/sql/parse.y > index f4fdf58f2..874a67a9b 100644 > --- a/src/box/sql/parse.y > +++ b/src/box/sql/parse.y > @@ -318,10 +318,8 @@ tcons ::= UNIQUE LP sortlist(X) RP. > SQL_INDEX_TYPE_CONSTRAINT_UNIQUE);} > tcons ::= CHECK LP expr(E) RP onconf. > {sql_add_check_constraint(pParse,&E);} > -tcons ::= FOREIGN KEY LP eidlist(FA) RP > - REFERENCES nm(T) eidlist_opt(TA) refargs(R) defer_subclause_opt(D). { > - sql_create_foreign_key(pParse, FA, &T, TA, D, R); > -} > +tcons ::= foreign_key_def. 2. Sorry for a nit, but I do not like _def for non-struct things. Why not just foreign_key? For example, 'expr' rule is just 'expr', not 'expr_def'. The same about other new _def prefixes here and in the last commit. > + > %type defer_subclause_opt {int} > defer_subclause_opt(A) ::= . {A = 0;} > defer_subclause_opt(A) ::= defer_subclause(A). > @@ -1444,22 +1442,38 @@ cmd ::= ANALYZE. {sqlite3Analyze(pParse, 0);} > cmd ::= ANALYZE nm(X). {sqlite3Analyze(pParse, &X);} > > //////////////////////// ALTER TABLE table ... //////////////////////////////// > -cmd ::= ALTER TABLE fullname(X) RENAME TO nm(Z). { > - pParse->constraint->table_name = X; > +cmd ::= alter_table_start alter_table_action . 3. The same. How about 'alter_table_action' -> 'alter_table'? Also, as I understand, you did not inline alter_table_start here because you need its C code be executed before alter_table_action, right? Then how about a comment on it? > + > +alter_table_start ::= ALTER TABLE fullname(Z) . { > + pParse->constraint->table_name = Z; > + pParse->constraint->name.n = 0; > +} > + > +alter_table_action ::= add_constraint_def. > +alter_table_action ::= drop_constraint_def. > +/** RENAME is ANSI extension, so it comes as a very special case. */ > +alter_table_action ::= rename. 4. It is an extension but why is it special? It is just one of the ways of table alteration. > + > +rename ::= RENAME TO nm(Z). { > sql_alter_table_rename(pParse, &Z); > } > > -cmd ::= ALTER TABLE fullname(X) ADD CONSTRAINT nm(Z) FOREIGN KEY > - LP eidlist(FA) RP REFERENCES nm(T) eidlist_opt(TA) refargs(R) > - defer_subclause_opt(D). { > - pParse->constraint->table_name = X; > - pParse->constraint->name = Z; > - sql_create_foreign_key(pParse, FA, &T, TA, D, R); > +add_constraint_def ::= add_constraint_start constraint_def. > + > +add_constraint_start ::= ADD CONSTRAINT nm(Z). { > + pParse->constraint->name = Z; > } > > -cmd ::= ALTER TABLE fullname(X) DROP CONSTRAINT nm(Z). { > - pParse->constraint->table_name = X; > - sql_drop_foreign_key(pParse, &Z); > +constraint_def ::= foreign_key_def. > + > +foreign_key_def ::= FOREIGN KEY LP eidlist(FA) RP REFERENCES nm(T) > + eidlist_opt(TA) refargs(R) defer_subclause_opt(D). { > + sql_create_foreign_key(pParse, FA, &T, TA, D, R); > +} > + > + 5. Double empty-line. > +drop_constraint_def ::= DROP CONSTRAINT nm(Z). { > + sql_drop_foreign_key(pParse, &Z); > } > > //////////////////////// COMMON TABLE EXPRESSIONS //////////////////////////// >