Here's a guess, as I'm not familiar with your particular Database and DBD.

It looks like the DBD is treating your value as in integer.  Perhaps the DBD 
looks at the first part of the string, and thinks, "here's a number, so I'll 
pass an integer type to the database engine".

Suggestion: try adding a type attribute to the the bind_param call, forcing the 
value to treated as a CHAR type.

-----Original Message-----
From: David Wu [mailto:[EMAIL PROTECTED]
Sent: Friday, November 10, 2006 4:34 PM
To: dbi-users@perl.org
Subject: Possible Problem with bind_param


Hi all,

I came across some funny behavior in Perl with the DBI package, and I  
don't know how to explain it or why it is happening.  I've tried  
googling it, but haven't found anything yet.  Here is the scenario:

I have some code that automatically tries to update a user's email  
address if it has changed when they come through using an  
integration.  However, it seems that although there was no error with  
the database, the update does not go through.  Here is the code for  
reference:

             my $sql = "UPDATE m_user SET email = ?, first_name = ?,  
last_name = ? WHERE id = ?;";
             my $sth = $dbh->prepare($sql);
             $sth->bind_param(1, $get_vars->{new_email});
             $sth->bind_param(2, $get_vars->{userfirstname});
             $sth->bind_param(3, $get_vars->{userlastname});
             $sth->bind_param(4, $api_user_id);
             $sth->execute;
             $sth->finish;

So, as an example, say somehow the value of the previous email  
address for this one user was "341".  I print out the value of  
"$get_vars->{new_email}" before and after the SQL statement, and the  
value is what I expect it to be, something like  
"[EMAIL PROTECTED]".  There are no errors and I hit the "$dbh- 
 >commit" line.  But if I run the query to retrieve the email of that  
same user, the email hasn't changed.  Also, Rich helped me to tail  
the database logs so that I could see the query as it was being  
executed, and I saw that it has truncated the value for the email,  
looking something like this: "UPDATE m_user SET email = 341,  
first_name = ...".

So this leads me to believe that there is something in the Perl that  
is causing the value to be truncated, something to do with bind_param  
or something like that.  I think it doesn't like the underscore  
character, or something.  What I don't understand is that other  
values have been working, like "[EMAIL PROTECTED]" or  
"[EMAIL PROTECTED]", but the moodle ones doesn't  
work.  However, I haven't been able to find any explanation or fix.

I've also tried reforming the query like "UPDATE m_user set email =  
'" . $get->vars->{new_email} ."', first_name = '" . $get->vars-> 
{userfirstname} . "', last_name = '" . $get_vars->{userlastname} . '"  
WHERE id = " . $api_user_id . "';";, but it wouldn't execute correctly.

I can correctly update the email directly in the database and in a  
perl command line script that uses the same format of the code as  
what I included above, but it won't work within the application.

I was wondering if anyone else ever encountered anything like this or  
new of a solution?  I'm using Perl 5.8.7 and DBI 1.52 and  PostgreSQL  
8.1.3 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.3.5 (Debian  
1:3.3.5-13) as the database.

Thanks,

Dave
[EMAIL PROTECTED]

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