Question

I am relatively new to Perl.I have been trying to insert data to database from a text file using a CGI script.I have written code for it and it’s working properly.but when i try to impose a limit on the data that is inserted using LIMIT keyword there is a problem.Please check where i am going wrong and what needs to be amended.Thanks for your advice.

here is the code

#!/usr/bin/perl

use warnings;
use strict;
use CGI ':standard';
use DBI;

if(param())
{
my @params=param();
my $limit=param('limit')||'';


my $dbh =DBI->connect("DBI:mysql:sample","root","");
my $var="LOAD DATA LOCAL INFILE 'C:/test.txt' INTO TABLE sample2 FIELDS TERMINATED       BY '\n' WHERE LIMIT 0,$limit";
my $sth = $dbh->do($var) or die "prepare failed: " . $dbh->errstr();
print $sth ."Records inserted";

$sth->finish();
$dbh->disconnect();

print
header(),
start_html(
-title=>'Welcome',
-text=>'#520063'
),
#h1("Records have been displayed"),
end_html();

}

else
{
print
header(),
start_html('A Simple Form'),
h1('Please enter the limit '),
start_form(),
'Limit: ',
textfield(-name=>'limit'),
br(),
#'Phone Number: ',
#textfield(-name => 'number'),
#br(),
submit(),
end_form(),
end_html();
} 

Answer 1

Without an error message I can’t be totally sure, but the problem is likely in your SQL.

LOAD DATA LOCAL INFILE 'C:/test.txt'
INTO TABLE sample2
FIELDS TERMINATED BY '\n'
WHERE LIMIT 0,$limit

There’s problems.

• There WHERE clause is empty (LIMIT is not part of the WHERE clause)
• LOAD DATA INFILE does not take a WHERE clause
• LOAD DATA INFILE does not take a LIMIT clause

Basically that whole last line won’t work. In general, if a SQL command doesn’t work in a program try firing up the MySQL command line and debug the command there.

LOAD DATA INFILE does not have a way to limit how many lines it will pull in, this is an oft requested feature. To work around it I would suggest copying and truncating the file before feeding it to MySQL.