CGI with PERL - quick start

Oh yeah, databases. simple answer: use MySQL and use DBI

#! /usr/bin/per

use DBI; # to access your MySQL database

# connect to your MySQL database (substitute appropriate database name, username and password)
my $dbh = DBI->connect("DBI:mysql:database_name", "username", "password") || die ("Couldn't connect to DB: $!");

# create an SQL query to get at some of your data
my $sth = $dbh->prepare("SELECT * FROM customer WHERE country=? AND province=?");

# run the SQL query
$sth->execute('Canada', 'Ontario');

# work with the resulting data
while (my $rowHash = $sth->fetchrow_hashref) {
  print "first name: $rowHash->{'firstname'}  last name: $rowHash->{'lastname'}";
}

The rest is up to your knowledge of SQL.

Good luck

Tom

tom this is a quick start? :))) this study for my entire life:))

Just joking today I got some books such as :

CGI Prgramming with Perl ( O'Reilly )
CGI Prigramnng 101 Perl for the World Wide WEB ( Hamilton)
Custom CGI Scripting with Perl
Instant CGI/PERL

so it seems I will not need yor help ( hope ) but just in case I'll keep this question open untill I finish my project if you don't mind.

thanks tom

Luxana

HI Tom,

I went throught book and I'm trying to make one of the scripts there using DBI database. This script is address book but I got a problem there with creating query there and I'm not realy clear what I'm doing there. The book wich I'm following have a lot of mistakes so for beginner as I'm it is hell:-) I fixed lots of mistakes by my self using just common sense but my problem is:

Can't call method "prepare" on an undefined value at /usr/lib/cgi-bin/address_book.cgi line 264.

here is part of script and line 264:

my $where_clause;
if ($cgi->param('exactmatch')) {
      $where_clause = join(" and",
                              map ($_
                                    . " = \""
                                    . $criteria{$_} . "\"", (keys %criteria)));
}      else      {
      $where_clause = join(" and",
                              map ($_
                                    . " like \"%"
                                    . $criteria{$_} . "\"", (keys %criteria)));
}
$where_clause =~ /(.*)/;
$where_clause = $1;

$sql = $sql . " where " . $where_clause if ($where_clause);

my $sth = $dbh->prepare($sql)      # here is line 264
      or die "Cannot prepare: " . $dbh->errstr();

no idea what I'm missing there. Thanks for your help if you need more info please let me know pls....

thanks tom

lubo

No problems.

The line my $sth = $dbh->prepare($sql) queries the database using the database handle ($dbh) that you need to set up first. This is usually done somewhere BEFORE this line using something like:

my $dbh = DBI->connect($data_source, $username, $auth);

$data_source is the name of the database (you might need to talk to your server administrator or web service to get the exact information)
$username is the username of the DATABASE user. This is sometimes the same as your logon for your website, but not always. Again, check with you web service provider.
$auth is the password for this username.

so usually the line looks something like:

my $dbh = DBI->connect("DBI:mysql:databaseName", "myUserName", "myPassword");

Replace the stuff in quotes with the appropriate information of course.

And don't forget, near the start of your script, make sure you have

use DBI;

Hope this helps! For more information on the DBI module, check out cpan (www.cpan.org). http://cpan.uwinnipeg.ca/htdocs/DBI/DBI.html


Cheers

Tom

Tom did a great job!
I have nothing else to add - but just to say - tom has set you up for a quick start.
Without that information - you wont go anywhere...

yes I know and he did more than gerat job :) that is why https://www.experts-exchange.com/questions/21157261/points-for-tomaugerdotcom.html
and I would like to keep this discusion here and I know that it is beyoud my quick start question and try to somehow fix my problem with my script:-)

thanks Tom

lubo

Thanks guys. I appreciate it - it makes a big difference when people appreciate a detailed answer.

Best of luck!

Tom