After stripping out comments and so forth of course ...
--- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users [mailto:sqlite-users- >boun...@mailinglists.sqlite.org] On Behalf Of petern >Sent: Sunday, 10 December, 2017 22:37 >To: SQLite mailing list >Subject: Re: [sqlite] Retrieving constraint name > >Igor/Cezary, > >It is remarkable how 'struct Parse' already contains the constraint >name as >Cezary pointed out. >-> Token constraintName;/* Name of the constraint currently being >parsed */ >But is not included in the 'struct FKey' linked list node that is >reeled in >to produce columns in the PRAGMA report. >For the official release, presumably, test cases would have to be >added in >addition to simply hooking it up as suggested. > >In the meantime, parsing wouldn't be difficult even with primitive >built-in >SQL string functions. Consider how the constraint name must occur >within >the comma delimited part of the well formed CREATE TABLE statement. >When >obtained from sqlite_master, the statement is guaranteed to be well >formed. Simply examine each comma delimited candidate part. If >present, >the first word between keyword CONSTRAINT and keyword REFERENCES is >the >constraint name. > >Peter > > > > > > > > > >On Sun, Dec 10, 2017 at 7:29 PM, Igor Korot <ikoro...@gmail.com> >wrote: > >> Hi, >> >> On Sun, Dec 10, 2017 at 8:30 PM, Cezary H. Noweta ><c...@poczta.onet.pl> >> wrote: >> > Hello, >> > >> > On 2017-12-11 01:04, Igor Korot wrote: >> > >> >> On Sun, Dec 10, 2017 at 5:01 PM, Cezary H. Noweta ><c...@poczta.onet.pl> >> >> wrote: >> > >> > >> >>> On 2017-12-10 07:21, Igor Korot wrote: >> > >> > >> >>>> The CREATE TABLE statement supports the following syntax: >> >>>> >> >>>> CREATE TABLE( <column_name_list>, CONSTRAINT <fk_name> FOREIGN >> >>>> KEY(<fk_field>) REFERENCES <ref_table>(ref_column_list>); >> > >> > >> >>>> [...] If not - does this mean that the only way to get the >name is to >> >>>> parse the >> >>>> sql >> >>>> from sqlite_master? Or there is a better way? >> > >> > >> >>> The answer is ``not''. Constraint names are ignored and >disappearing >> >>> without >> >>> a trace except for ``CHECK'' constraint (the name is used to >build an >> >>> error >> >>> message). Unparsed ``sql'' column of ``sqlite_master'' is the >sole >> place >> >>> which contains an indirect info about ``FOREIGN KEY'' >constraint's >> name. >> > >> > >> >> Thank you for confirming. >> > >> > You are welcome. BTW, SQLite parses SQL every time it creates a >table >> > (by a SQL command or after an opening of BTree file) -- I believe >there >> > is no better way. You do not need to parse SQL on your own (it is >hard, >> > if not impossible, to establish a link between a name and a >particular >> > constraint). All you need is to append ``char *'' field to >``struct >> > FKey'' and to inject a function >``build.c:sqlite3CreateForeignKey()'': >> > ``pParse->constraintName'' will contain the constraint's name >(note >> > that the name is not dequoted -- you will have to dequote it; >look at >> > ``build.c:sqlite3AddCheckConstraint()'' to know how assigning of >a >> > constraint's name is done). This will allow you to build your own >map of >> > ``FOREIGN KEY'' names. For example, if you want to expand >``PRAGMA >> > foreign_key_list'', go to ``pragma.c:sqlite3Pragma():case >> > PragTyp_FOREIGN_KEY_LIST:'' and append new FKey's field. >> >> Thank you, but I need to keep the official SQLite code. >> >> >> > >> > >> > -- best regards >> > >> > Cezary H. Noweta >> > _______________________________________________ >> > sqlite-users mailing list >> > sqlite-users@mailinglists.sqlite.org >> > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite- >users >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@mailinglists.sqlite.org >> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite- >users >> >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
