One is a correlated subquery and the other isn't. Do I get a prize?
--- () ascii ribbon campaign against html e-mail /\ www.asciiribbon.org > -----Original Message----- > From: [email protected] [mailto:sqlite-users- > [email protected]] On Behalf Of YAN HONG YE > Sent: Monday, 03 December, 2012 18:26 > To: [email protected] > Subject: [sqlite] what diffrent with this two sql command? > > SELECT c FROM mytable AS m1 WHERE NOT EXISTS (SELECT b FROM mytable AS m2 > WHERE m2.b = m1.c); > > SELECT c FROM mytable WHERE NOT EXISTS (SELECT b FROM mytable WHERE b = > c); > > > > > Sincerely, > Cordialement / Best Regards / Mit freundlichen Grüßen / Cordiali saluti ! > ___________________________________________ > --------------------------------------------------------------------------- > YE YANHONG/???- DASI/DRDS/ITVC/APFS/AVPM > PSA PEUGEOT CITROEN(CHINA) AUTOMOTIVE TRADE CO,. LTD SHANGHAI BRANCH > Tel: (+86) 21-2419 5488 Mobile:(+86) 13816808338 Fax: (+86) 21-2419 5004 > PSA internal call: 49 5488 > Email: [email protected]<mailto:[email protected]> > Address: 6th Floor, Building 1, No. 1528, Gumei Road, > Xuhui District, Shanghai > Post Code:200233 > ??: ?????????1528?A1?6? > > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
