I am trying to insert a record into a MySQL database using Perl DBI. I am not getting any errors but the insert is not working. However, I am able to successfully fetch records from the database using DBI.
Here is the code that does the insert:
#!"C:\xampp\perl\bin\perl.exe"
use diagnostics;
use DBI;
use strict;
use warnings;
my $driver = "mysql";
my $database = "mysql";
my $dsn = "DBI:$driver:database=$database";
my $userid = "root";
my $password = "password";
my $buffer;
my @pairs;
my $pair;
my $name;
my $value;
my %FORM;
# Read in text
my $ENV;
$ENV{'REQUEST_METHOD'} =~ tr/a-z/A-Z/;
if ($ENV{'REQUEST_METHOD'} eq "GET")
{
$buffer = $ENV{'QUERY_STRING'};
}
# Split information into name/value pairs
@pairs = split(/&/, $buffer);
foreach $pair (@pairs)
{
($name, $value) = split(/=/, $pair);
$value =~ tr/+/ /;
$value =~ s/%(..)/pack("C", hex($1))/eg;
$FORM{$name} = $value;
}
my $first_name= $FORM{name};
my $address = $FORM{address};
my $city = $FORM{city};
my $occupation = $FORM{occupation};
my $age = $FORM{age};
my $dbh = DBI->connect("dbi:mysql:dbname=mysql", "root", "password",{ AutoCommit => 0,RaiseError => 1}, ) or die ("Couldn't connect to database: ") , $DBI::errstr;
# my $sth = $dbh->prepare("INSERT INTO persons
# (FirstName, LastName,Address,City)
# values
# ($first_name, $last_name,$address,$city)");
my $query = "insert into userrecords(Address,Age,City,Name,Occupation)
values (?, ?, ?, ?, ?) ";
my $statement = $dbh->prepare($query) or die ("Couldn't connect to database: "), $DBI::errstr;
$statement->execute($address,$age,$city,$name,$occupation) or die ("Couldn't connect to database: "), $DBI::errstr;
$dbh->disconnect();
my $URL = "http://.....:81/cgi-bin/showdata.cgi";
print "Location: $URL\n\n";
exit(0);
When I run my code in the Padre IDE, I get the following errors:
****Error*********
Useless use of a variable in void context at InsertRecord.cgi line 50 (#1)
(W void) You did something without a side effect in a context that does
nothing with the return value, such as a statement that doesn't return a
value from a block, or the left side of a scalar comma operator. Very
often this points not to stupidity on your part, but a failure of Perl
to parse your program the way you thought it would. For example, you'd
get this if you mixed up your C precedence with Python precedence and
said
$one, $two = 1, 2;
when you meant to say
($one, $two) = (1, 2);
Another common error is to use ordinary parentheses to construct a list
reference when you should be using square or curly brackets, for
example, if you say
$array = (1,2);
when you should have said
$array = [1,2];
The square brackets explicitly turn a list value into a scalar value,
while parentheses do not. So when a parenthesized list is evaluated in
a scalar context, the comma is treated like C's comma operator, which
throws away the left argument, which is not what you want. See
perlref for more on this.
This warning will not be issued for numerical constants equal to 0 or 1
since they are often used in statements like
1 while sub_with_side_effects();
String constants that would normally evaluate to 0 or 1 are warned
about.
Useless use of a variable in void context at InsertRecord.cgi line 59 (#1)
Useless use of a variable in void context at InsertRecord.cgi line 60 (#1)
Use of uninitialized value in transliteration (tr///) at InsertRecord.cgi line
23 (#2)
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
To help you figure out what was undefined, perl will try to tell you the
name of the variable (if any) that was undefined. In some cases it cannot
do this, so it also tells you what operation you used the undefined value
in. Note, however, that perl optimizes your program and the operation
displayed in the warning may not necessarily appear literally in your
program. For example, "that $foo" is usually optimized into "that "
. $foo, and the warning will refer to the concatenation (.) operator,
even though there is no . in your program.
Use of uninitialized value $ENV{"REQUEST_METHOD"} in string eq at
InsertRecord.cgi line 24 (#2)
Use of uninitialized value $buffer in split at InsertRecord.cgi line 29 (#2)
Location: http://.......:81/cgi-bin/showdata.cgi
Press any key to continue . . .
***********END***********************
What is the issue?
What happens when you replace your code with this:
#!"C:\xampp\perl\bin\perl.exe"
use strict;
use warnings;
use diagnostics;
use DBI;
use CGI qw[param redirect];
my $driver = "mysql";
my $database = "mysql";
my $dsn = "DBI:$driver:database=$database";
my $userid = "root";
my $password = "password";
my $dbh = DBI->connect("dbi:mysql:dbname=mysql", "root", "password",
{ AutoCommit => 0,RaiseError => 1}, )
or die "Couldn't connect to database: ", $DBI::errstr;
my $query = "insert into userrecords(Address,Age,City,Name,Occupation)
values (?, ?, ?, ?, ?) ";
my $statement = $dbh->prepare($query)
or die "Couldn't connect to database: " , $DBI::errstr;
$statement->execute(param('address'), param('age'), param('city'),
param('name'), param('occupation'))
or die "Couldn't connect to database: " , $DBI::errstr;
$dbh->disconnect();
my $URL = "http://.....:81/cgi-bin/showdata.cgi";
print redirect($URL);
I've basically made two changes:
die
.I'm made no substantive changes to the code, but at least we now have a clean version to go with.
Update: D'oh. It's obvious now the code is cleaned up a bit. If you have "Autocommit" turned off, then you need to commit your changes. Add $dbh->commit
between the calls to execute()
and disconnect()
.
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