> if any single column in those two rows is NULL. OK, I got it and that will make it even less likely that this situation will occur. I think we got this exhausted now.
RBS On Fri, Oct 2, 2015 at 6:24 PM, Richard Hipp <drh at sqlite.org> wrote: > On 10/2/15, Bart Smissaert <bart.smissaert at gmail.com> wrote: > > Do you mean that is only valid if there are no rows where all columns are > > NULL? > > No, I mean that two rows can be identical (not distinct) event if > there is a unique index on all columns, if any single column in those > two rows is NULL. Example: > > SQLite version 3.8.11 2015-07-15 23:15:59 > Enter ".help" for usage hints. > Connected to a transient in-memory database. > Use ".open FILENAME" to reopen on a persistent database. > sqlite> create table t1(a,b,c); > sqlite> create unique index t1u on t1(a,b,c); > sqlite> insert into t1(a,b,c) values(1,null,3),(1,null,3),(1,null,3); > sqlite> > > -- > D. Richard Hipp > drh at sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
