Hello paulski82,

I am not an SQL user, because I am working with MySQL so maybe my observations are wrong. But as far as I know SQL and MySQL are really close to each other so the syntax is the same 99% of the time.

A few things that I noticed on your code:

my $sql_query = "SELECT * FROM export";

my $dbh = DBI->connect ("dbi:CSV:f_dir:/root", undef, undef, {
    f_ext      => ".csv",
    RaiseError => 1,
}
);
[download]

You are preparing a my $sql_query = "SELECT * FROM export"; before connecting.

Because you are executing the command after through:

my $sth = $dbh->prepare($sql_query);
$sth->execute();
[download]

Your code will compile and execute without any problem, but it is a bit confusing in a human readable form and maybe also confuses you on the process.

I would suggest you modify your code like this:

$dbh = DBI->connect ("dbi:CSV:f_dir:/root", undef, undef, {
        f_ext      => ".csv/r",
        RaiseError => 1,
        }) or die "Cannot connect: $DBI::errstr";

my $sql_query = "SELECT * FROM export";

my $sth = $dbh->prepare($sql_query);
$sth->execute();
[download]

Observe the line that I have added or die "Cannot connect: $DBI::errstr", it will help you see a possible error if for any reason can not connect.

I would also suggest you modify the line:

my $sql_query = "SELECT * FROM export";
my $sth = $dbh->prepare($sql_query);
$sth->execute();
[download]

To:

my $sth = $dbh->prepare ("SELECT * from export");
$sth->execute();
[download]

It is more clear what you are doing and also less coding lines make your code more efficient and faster.

At the end of your code when you finish, I would suggest to disconnect from your database.

Sample of code:

$sth->finish();
$dbh->disconnect();
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From the book Programming the Perl DBI written by Alligator Descartes & Tim Bunce, I have taken the following line:

It is important to free up both your local machine resources and, more importantly, valuable database resources.

As the rest of the monks suggested I think you are missing something small in the:

my $dbh = DBI->connect ("dbi:CSV:f_dir:/root", undef, undef, {
    f_ext      => ".csv",
    RaiseError => 1,
}
);
[download]

I would suggest you to read the DBD::CSV - DBI driver for CSV files it contains code analysis and samples of code. I am sure by experimenting you will find your error.

Hope this helps.