Perl user input into SQL Like statement - sql

Question

Im trying to get user input and send it through to the SQL Like statement. But Im getting error: Can't call method "bind_param" on an undefined.
My Original code :
#!/usr/bin/perl
use DBI;
#use DBD::Oracle;
use strict;
use warnings;
use CGI;
print "Enter INCD number : ";
my $input = <>;
chomp $input;
my $DSN = 'driver={SQL Server};Server=ddsfs1; database=sdfds;TrustedConnection=Yes';
my $dbh = DBI->connect("dbi:ODBC:$DSN")
#print "connected.."
or die "$DBI::errstr\n";
my $query = $dbh->prepare("SELECT TOP 20 Id
,Created
,Updated
,Message
FROM FrameworkDEV3.Log.Entry
where Message like ?
and Created >= DATEADD(day, -10, GETDATE())
order by Created desc");
$sth->bind_param(1, '%$input%');
print $sth;
$sth->execute;
#DBI::dump_results($sth);
while( my #data = $query->fetchrow_array())
{
foreach(#data) {
print "[$_]";
}
print "\n\n";
}
$sth->finish;
$dbh->disconnect;
#print "Connected..";
print "\n";
Following code is fixed as per comments from Dave and Jim :
my $sth = $dbh->prepare("SELECT TOP 20 Id
,Created
,Updated
,Message
FROM FrDEVsd.Log.Entry
where Message like ?
and Created >= DATEADD(day, -10, GETDATE())
order by Created desc");
$sth->bind_param(1, "%$input%");
print $sth;
$sth->execute;
#DBI::dump_results($sth);
while( my #data = $sth->fetchrow_array())
{
foreach(#data) {
print "[$_]";
}
print "\n\n";
}
$sth->finish;
$dbh->disconnect;
print "\n";
The error im getting now is
DBI::st=HASH(0x2a9a480)

Answer 1

In your code:
my $query = $dbh->prepare("SELECT TOP 20 Id
,Created
,Updated
,Message
FROM sdada.ada.asd
where Message like ?
and Created >= DATEADD(day, -10, GETDATE())
order by Created desc");
my $sth->bind_param(1, "%$input%");
Notice the prepared statement is stored in a variable named $query, but you attempt to bind using $sth which was never set and is undefined. That is what the error message was telling you.
Use the same variable name both places (and later when you execute the statement) to fix the problem.

Answer 2

You've already been given a fish. Perhaps we can show you how to catch your own in the future.
This is your error:
Can't call method "bind_param" on an undefined
You call bind_param() on this line:
my $sth->bind_param(1, "%$input%");
So you're defining a variable (called $sth) and immediately expecting that variable to be an object that you can call a method on. When you define a variable with my the variable is initialised to undef unless you assign something to it like this:
my $var = 'something';
Your code is the equivalent of this.
my $sth = undef;
$sth->my $sth->bind_param(1, "%$input%");
Do you see the problem now?
In DBI code you'll often see the the variable $sth used to store the statement handle that we use to execute a statement. I suspect you've copied this from some example DBI code and taken the variable name from there. If $sth was a statement handle then you could certainly call the bind_param() method on it.
So $sth needs to be a statement handle. And we create one of those by calling the prepare() method on a database handle.
my $sth = $dbh->prepare($some_sql);
Oh, but wait.... you already have a line that looks a lot like that:
my $query = $dbh->prepare("SELECT ...");
So it looks to me like you started writing your own code, using $query as the variable to hold the statement handle. You then copied the bind_param() line from some sample code. That didn't compile, because it used $sth, which you hadn't declared, so you just stuck a my in front of it to get around that problem? Does that sound at all accurate?
What you really wanted was to call bind_param() on the statement handle that you had already created.
$query->bind_param(1, "%$input%");
But, to be honest, I think it's a good idea to stick with the "standard" names for DBi-related variables. It's what your maintenance programmer (which might well be you in six months time!) will expect to see.
So I'd change the prepare() line to:
my $sth = $dbh->prepare("SELECT ...");
And leave the bind_param() call as it is. You'll need to change the fetchrow_array() to be called on $sth as well.