Re: = or := ?
От | Zlatko Matic |
---|---|
Тема | Re: = or := ? |
Дата | |
Msg-id | 006301c554b3$cee15440$48778353@zlatkovyfkpgz6 обсуждение исходный текст |
Ответ на | Connecting to Postgres using Rekall (Susemail <susemail@hawaii.rr.com>) |
Список | pgsql-general |
thanks. ----- Original Message ----- From: "Michael Glaesemann" <grzm@myrealbox.com> To: "Zlatko Matic" <zlatko.matic1@sb.t-com.hr> Cc: <pgsql-general@postgresql.org> Sent: Monday, May 09, 2005 11:30 AM Subject: Re: [GENERAL] = or := ? > > > On May 9, 2005, at 18:00, Zlatko Matic wrote: > >> This is a newbie question: what is the difference between using = and >> := in plpgsql function ? > > In pl/pgsql, > > := is assignment > = is a logical comparison for equality > > Some languages, such as perl, use = for assignment and == for logical > comparison. > > x = 1 > is a boolean result > > x := 1 > gives x the value of 1 > > Quick example: > > x := 2; -- gives x the value of 2 > > IF (x = 1) THEN -- x = 1 is false > x := 3; -- skipped > END IF; > RETURN X; -- returns 2 > > Again: > x := 1; -- gives x the value of 1 > > IF (x = 1) THEN -- x = 1 is true > x := 3; -- perform assignment > END IF; > RETURN x; -- returns 3 > > Hope this helps. > > Michael Glaesemann > grzm myrealbox com > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org >
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