Re: binding values to sql statement in DBI perl - Mailing list pgsql-novice

Here is the code I'm trying to execute:

I'm accepting user input for the semester and gathering the data for that particular semester.

print " Enter the semester:\n";
$f_semester = <STDIN>;

# collecting rows of section,section_loc table to insert into interface table

my $sth = $dbh->prepare('SELECT course_id, course_name,section.section_id,day,time,enroll_capacity,room_capacity,bldg,instructor_id,instructor_name,semester,notes FROM section,section_location where section.section_id = section_location.section_id AND section.semester=?'
)

                        or die "couldn;t prepare statement:".$dbh->errstr;

$sth->bind_param(1, $f_semester);
my @data;
$sth->execute($f_semester);

while(@data = $sth->fetchrow_array())
{
              
   my $insert_csv = "INSERT INTO interface_write(course_id,course_name,credit_hours,section_id,days,time,cap_enroll,room_cap,bldg,instructor_id,instructor_name,semester,notes)values(?,?,?,?,?,?,?,?,?,?,?,?,?)";
$dbh->do($insert_csv,undef,$data[0],$data[1],$data[2],$data[3],$data[4],$data[5],$data[6],$data[7],$data[8],$data[9],$data[10],$data[1
1],$data[12]);
}


$sth->finish;
}

I first tried it without passing the variable to $sth->execute;

It doesn;t display any error but it seems like it is not entering the while loop.
I am new to postgres and dbi perl , and i'm tryinng to figure this one out. Is there any module that has to be included to use the bind_param . I already included

 

use DBI qw(:sql_types);
I also need to include the semester in single quotes to search in the table, will bind_param enclose the text in quotes or how does it work.
_

Any help on this would be greatly appreciated.

Thanks and regards

Deepblues











On Apr 6, 2005 7:28 PM, Michael Fuhr <mike@fuhr.org> wrote:
> On Wed, Apr 06, 2005 at 11:42:55AM -0500, Deepblues wrote:
> >
> > I am having trouble with binding values to SQL statements using dbi perl.
> >
> > The scenerio is as follows :
> >
> > I have a scheduling database that holds the listings of classes and
> > there schedules for a university. I am trying to query the database to
> > display the listings of classes , sections for  a particular semester
> > that the user enters.
> > I am able to get the results with the actual value but then when I use
> > the variable which holds the values of the semester the user entered
> > and try querying , it displays an error message saying
> >
> > "unbound place holder "
>
> Could you post a small but complete program that exhibits the
> problem?  Without seeing your code we can only guess what might be
> wrong.  Also, please post the complete, exact text of the error
> message (copied and pasted, not typed manually).
>
> I suspect the real error is something like the following:
>
> DBD::Pg::st execute failed: execute called with an unbound placeholder at ./foo line 14.
>
> If that's the case, then you might have called $sth->execute() with
> no arguments when you should have called it with arguments, e.g.,
> $sth->execute($variable).  But that's just a guess; without seeing
> your code we can't be sure.
>
> --
> Michael Fuhr
> http://www.fuhr.org/~mfuhr/
>


--
Deepti Mandava
Graduate Teaching Assistant,
The University of Kansas
Lawrence, KS  66045-7546