Thanks for the clarification. I suggest you use your words of explanation in the document to make it clearer instead of a simple sentence.
> -----Original Message----- > From: sqlite-users <[email protected]> > On Behalf Of Keith Medcalf > Sent: Tuesday, October 29, 2019 2:29 PM > To: SQLite mailing list <[email protected]> > Subject: Re: [sqlite] https://www.sqlite.org/draft/gencol.html > Typo > > > On Tuesday, 29 October, 2019 12:25, Doug <[email protected]> > wondered: > > >The draft says "Nor may a generated column depend on the ROWID." > > >If my table uses ROWID by default: > > >CREATE TABLE foo (id INTEGER PRIMARY KEY, a INTEGER, b AS > (id+a)); > > >where id is ROWID by default, is the generated column disallowed > because > >it has an implied dependency on ROWID? > > sqlite> CREATE TABLE foo (id INTEGER PRIMARY KEY, a INTEGER, b AS > (id+a)); > sqlite> insert into foo values (1,1),(2,1),(3,1); > sqlite> select * from foo; > 1|1|2 > 2|1|3 > 3|1|4 > sqlite> create table bar (a INTEGER, b AS (_rowid_ + a)); > Error: no such column: _rowid_ > sqlite> create table bar (a INTEGER, b AS (rowid + a)); > Error: no such column: rowid > sqlite> create table bar (id INTEGER PRIMARY KEY, a INTEGER, b AS > (_rowid_+a)); > Error: no such column: _rowid_ > sqlite> create table bar (id INTEGER PRIMARY KEY, a INTEGER, b AS > (rowid + a)); > Error: no such column: rowid > sqlite> create table bar (_rowid_ INTEGER PRIMARY KEY, a INTEGER, > b as (_rowid_ + a)); > sqlite> insert into bar (a) values (1),(1),(1); > sqlite> select * from bar; > 1|1|2 > 2|1|3 > 3|1|4 > > So a generated column may not depend on the IMPLICITLY named rowid > (by whatever magic you want to use), but it may depend on an > EXPLICIT rowid (or alias). In other words, only explicitly named > columns are permitted. If you EXPLICITY named the rowid alias to > be _rowid_ it works without problem. Same rule applies to FOREIGN > KEY contraints which may only depend on EXPLICITLY named columns, > not the IMPLICIT rowid. > > -- > The fact that there's a Highway to Hell but only a Stairway to > Heaven says a lot about anticipated traffic volume. > > > > _______________________________________________ > sqlite-users mailing list > [email protected] > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite- > users _______________________________________________ sqlite-users mailing list [email protected] http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
