On Mon, 13 Aug 2007 13:07:43 -0500 "Kevin Grittner" <Kevin.Grittner@xxxxxxxxxxxx> wrote: > >>> On Mon, Aug 13, 2007 at 12:50 PM, in message <46C099F6.8050002@xxxxxxxxx>, > olivier boissard <olivier.boissard@xxxxxxxxx> wrote: > > I tried to use the except command in postgresql 8.1 > > I don't understand as it works > > When I read doc , I understand that it was like a difference betwwen two > > queries > > That isn't how I read it: > > "The EXCEPT operator returns the rows that are in the first result set > but not in the second." > > ( http://www.postgresql.org/docs/8.1/interactive/sql-select.html ) > > Are you seeing something different? > > This gets me all the eye color codes that don't start with the letter 'B'. > (There are of course easier ways to get that...) > > bigbird=> select * from "EyeColorCode" except select * from "EyeColorCode" where "eyeColorCode" like 'B%'; > eyeColorCode | descr | isActive | dotEyeColorCode > --------------+-----------------+----------+----------------- > GRN | Green | t | GRN > GRY | Gray | t | GRY > HAZ | Hazel | t | HAZ > MAR | Maroon | t | MAR > MUL | Multicolored | t | DIC > PNK | Pink | t | PNK > XXX | Unknown | t | UNK > (7 rows) > > -Kevin so is this faster than usiung 'where not exists' ?? Steve ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
