Thread: Case sensitivity

Case sensitivity

From
"Jason Tesser"
Date:

I am converting data from Access into Postgres and ran into an issue with case sensitivity. Can I write queries in Access that will be case insensitive without rewriting the queries.  So I would like to know if this be handled in Postgres or even if someone knows in Access.  Thank you.

Re: Case sensitivity

From
David Garamond
Date:
Jason Tesser wrote:
> I am converting data from Access into Postgres and ran into an issue
> with case sensitivity. Can I write queries in Access that will be case
> insensitive without rewriting the queries.  So I would like to know if
> this be handled in Postgres or even if someone knows in Access.  Thank
> you.

I believe no. You can index on LOWER(f) or UPPER(f) but that still
requires a query rewriting to WHERE LOWER(f) = .... You can also write
INSERT triggers to convert values to upper case, but that still requires
query rewriting if you're comparing with mixed-case values.

This has been discussed many times. See the archive for the various
threads on this.

To be safe, if you want your application to be portable, you should
always assume case-sensitivity. AFAIK, only Access, SQL Server, and
MySQL that are case-insensitive by default while others including
Postgres are case-sensitive. Any other popular DB that are
case-sensitive out there?

--
dave


Re: Case sensitivity

From
Klint Gore
Date:
On Tue, 10 Feb 2004 13:02:55 +0700, David Garamond <lists@zara.6.isreserved.com> wrote:
> To be safe, if you want your application to be portable, you should
> always assume case-sensitivity. AFAIK, only Access, SQL Server, and
> MySQL that are case-insensitive by default while others including
> Postgres are case-sensitive. Any other popular DB that are
> case-sensitive out there?

Sybase SQL Anywhere is not case sensitive by default.  It has a setting
to change it.

klint.

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Re: Case sensitivity

From
Andrew Sullivan
Date:
On Tue, Feb 10, 2004 at 01:02:55PM +0700, David Garamond wrote:
>
> I believe no. You can index on LOWER(f) or UPPER(f) but that still
> requires a query rewriting to WHERE LOWER(f) = .... You can also write
> INSERT triggers to convert values to upper case, but that still requires
> query rewriting if you're comparing with mixed-case values.

But you could do some tricks with rules (plus the indexes and
triggers you mentioned) in order to lower() or upper() the input, if
you happen to know where you're likely to have the problems.

It's certainly true, however, that from the point of view of keeping
your data clean, you want these steps handled before the data
actually gets into the database.

A

--
Andrew Sullivan  | ajs@crankycanuck.ca
The plural of anecdote is not data.
        --Roger Brinner