How to represent spaces in Perl's DBI properly - perl

Question

I have a record in an Informix table. The table columns look like this:
acct_no integer,
suffix char(1),
meter_num char(20),
date_read datetime year to second not null ,
counter smallint,
reading integer not null ,
typeofread char(1),
estimated char(1),
time_billed datetime year to second
Using Informix's dbaccess tool:
select *
from ws_mtrread
where acct_no = 113091000
and suffix = " "
order by date_read desc;
this result (newest shown) is returned and works whether or not I use one or two spaces for suffix.
acct_no 113091000
suffix
meter_num 34153205
date_read 2013-09-09 23:31:15
counter 0
reading 1240
typeofread g
estimated
time_billed 2013-10-22 11:48:21
However, this Perl DBI query
my $sql_statement =
"select * ".
"from ws_mtrread ".
"where acct_no = ? ".
"and suffix = ? ".
"order by date_read desc ; ";
does not work. I can fetch the row without specifying $suffix, so I know the row exists.
I believe this is an error on my part in representing the suffix. In this example suffix is equal to a string of two spaces.
How do I represent spaces correctly, so the query works? Here is the rest of the code I used to fetch the row.
my $test_acct_no = 113091000;
my $suffix = " ";
my $pt_sel_hdl = $DBHdl->prepare($sql_statement);
$pt_sel_hdl->execute($test_acct_no, $DBHdl->quote($suffix));
my $ws_mtr_read_rec_ref = $pt_sel_hdl->fetchrow_hashref;
After the call, $ws_mtr_read_rec_ref is undefined.

Answer 1

Don't use DBI's quote method here:
$pt_sel_hdl->execute($test_acct_no, $DBHdl->quote($suffix));
When you use ? placeholders in your SQL, the database driver will correctly parameterize the query arguments that you pass to execute. You are probably creating a query that is searching for the literal string " " (including the quotes) when you want to search for (just two spaces.)
So this should be all you need:
$pt_sel_hdl->execute($test_acct_no, $suffix);