Re: no records returned

James Moe <jimoe@sohnen-moe.com>

From: "James Moe" <jimoe@sohnen-moe.com>
To: "Postgresql General Mail List" <pgsql-general@postgresql.org>
Date: 2003-10-26T22:46:58Z
Lists: pgsql-general
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sat, 25 Oct 2003 20:19:49 -0700 (MST), Lynn.Tilby@asu.edu wrote:

>Could you explain to a newbie WHY the like and % at
>the end of the literal works when the normal select does 
>not?
>
  The "%" is a wildcard character in SQL, the same as "*" in many file systems. It 
matches 0 or more characters. Also "_" matches any single character, similar to 
"?", or "." in regular expressions.
  There is likely one or more spaces after the visible characters. Using a "%" 
after ZRAN matches ZRAN plus anything else following that pattern.
  The implementation of the LIKE operator is a somewhat uneven in my experience. 
Depending on the database it can only be used to match strings, or to do a 
case-insensitive compare, or is equivalent to "=" with "=" extended to string 
operations. In most cases, though, the best practice is to use it for strings 
especially when using regular expressions like "%"; and to use "=" for numeric and 
exact matching.


- -- 
jimoe at sohnen-moe dot com
pgp/gpg public key: http://www.keyserver.net/en/
-----BEGIN PGP SIGNATURE-----
Version: PGPfreeware 5.0 OS/2 for non-commercial use
Comment: PGP 5.0 for OS/2
Charset: cp850

wj8DBQE/nE7isxxMki0foKoRAkJjAJ9lpqeC8y+Go0tXclwIM8XzvaRd1QCgtn8i
26WzEwf8HNPY5iqY6ZckrmY=
=DY5x
-----END PGP SIGNATURE-----