select from (select ... ) must have alias. It should be
select from (select ... ) a On Tue, May 20, 2014 at 9:38 AM, YAN HONG YE <yanhong...@mpsa.com> wrote: > Hi, > Sorry, I use mysql, not in sqlite, in mysql ,I run this command, the > console show this error: do you know why? > Thank you very much! > > mysql> UPDATE adlbk20140520a > -> SET pflopf = ( > -> SELECT pflopf > -> FROM adl > -> WHERE adl.ref = adlbk20140520a.ref) > -> WHERE ( > -> SELECT COUNT(*) > -> FROM ( > -> SELECT 1 FROM adl > -> WHERE adl.ref = adlbk20140520a.ref > -> LIMIT 2 > -> ) > -> ) = 1; > ERROR 1248 (42000): Every derived table must have its own alias > mysql> > > > Message: 8 > > Date: Mon, 19 May 2014 09:55:25 +0300 > > From: Paul <de...@ukr.net> > > To: sqlite-users@sqlite.org > > Cc: sqlite-users@sqlite.org > > Subject: Re: [sqlite] how to write this commands? > > Message-ID: <1400482276.625069613.b8rdb...@frv38.fwdcdn.com> > > Content-Type: text/plain; charset="UTF-8" > > > > > > > UPDATE adla1 > > > SET pflopf = ( > > > SELECT pflopf > > > FROM adl > > > WHERE adl.ref = adla1.ref) > > > WHERE ( > > > SELECT COUNT(*) > > > FROM ( > > > SELECT 1 FROM adl > > > WHERE adl.ref = adla1.ref > > > LIMIT 2 > > > ) > > > ) = 1; > > > > > > Not all sure what LIMIT 2 does there. I think a SQL-92 version > > > would be > > > > > > > Limit, limits number of rows selected by ref. If we have found 2, no > need to lookup further. > > That's why it was said to be a slightly optimized version. Generally > this saves some disk reads. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
