Обсуждение: Regular Expressions and SELECT

Hi,
I'm working through Bruce Momjian's online tutorial on PostreSQL, and am
now trying to get my head around regular expressions.  The tutorial says
that ~ '^X' where 'X' is a character, will find table entries beginning
with that character.

When I try it ...

    SELECT * FROM testdb ~'^d' ;
    ERROR:  parser: parse error at or near "~"

I get this, irrespective of the regular expression that I use.  It _is_ a
tilde, isn't it ?  Or is my eyesight going ..?  :-(

Thanks.

D.

--
Desmond Coughlan          |'Io non mori, e non rimasi vivo'
desmond@zeouane.org
http://www.zeouane.org

Le Wed, Jan 22, 2003 at 10:08:12PM +0000, Desmond Coughlan a écrit ...

> I'm working through Bruce Momjian's online tutorial on PostreSQL, and am
> now trying to get my head around regular expressions.  The tutorial says
> that ~ '^X' where 'X' is a character, will find table entries beginning
> with that character.
>
> When I try it ...
>
>     SELECT * FROM testdb ~'^d' ;
>     ERROR:  parser: parse error at or near "~"
>
> I get this, irrespective of the regular expression that I use.  It _is_ a
> tilde, isn't it ?  Or is my eyesight going ..?  :-(

Perhaps a 'WHERE' wouldn't have gone astray.  Doh !!

Sorry about that.  :-)

D.

--
Desmond Coughlan          |'Io non mori, e non rimasi vivo'
desmond@zeouane.org
http://www.zeouane.org

On Wednesday 22 January 2003 02:07 pm, Desmond Coughlan wrote:
> Hi,
> I'm working through Bruce Momjian's online tutorial on PostreSQL, and am
> now trying to get my head around regular expressions.  The tutorial says
> that ~ '^X' where 'X' is a character, will find table entries beginning
> with that character.
>
> When I try it ...
>
>     SELECT * FROM testdb ~'^d' ;
>     ERROR:  parser: parse error at or near "~"
>
> I get this, irrespective of the regular expression that I use.  It _is_ a
> tilde, isn't it ?  Or is my eyesight going ..?  :-(
>
> Thanks.
>
> D.

You're missing the 'where clause', for example

SELECT * FROM testdb where name~'^d';

I won't comment on your eyesight ;)

-Doug

I haven't done this myself, but I strongly suspect the usage is more like

SELECT * FROM sometable WHERE somefield ~ '^d' ;

Doug Gorley | douggorley@shaw.ca

Hi,
I'm working through Bruce Momjian's online tutorial on PostreSQL, and am
now trying to get my head around regular expressions.  The tutorial says
that ~ '^X' where 'X' is a character, will find table entries beginning
with that character.

When I try it ...

    SELECT * FROM testdb ~'^d' ;
    ERROR:  parser: parse error at or near "~"

I get this, irrespective of the regular expression that I use.  It _is_ a
tilde, isn't it ?  Or is my eyesight going ..?  :-(

Thanks.

D.

--
Desmond Coughlan          |'Io non mori, e non rimasi vivo'
desmond@zeouane.org
http://www.zeouane.org