perl - print sql row

Question

I want to print all sql result of my perl script, I've connected to the database and I want to show the result of my sql query:

MySQL("SELECT * FROM test");

# define subroutine to submit MySQL command
 sub MySQL
 {   
     #Connect to the database.
     my $dbh = DBI->connect("DBI:mysql:database=database;host=ip",
     "login", 'password',
     {'RaiseError' => 1});

     my $query = $_[0];  #assign argument to string

     my $sth = $prepare($query);   #prepare query

     $sth->execute();   #execute query

     while (my @row = $sth->fetchrow_array)
        {
            print "@row\n";
        }
}

I have this errors:

Global symbol "$prepare" requires explicit package name at test3.pl line 34.
syntax error at test3.pl line 34, near "$prepare("
Global symbol "$sth" requires explicit package name at test3.pl line 36.
Execution of test3.pl aborted due to compilation errors.

Answer 1

Change this line:

my $sth = $prepare($query);

to

my $sth = $dbh->prepare($query);

and don't forget to close the $sth and $dbh handles after the while loop with:

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

Answer 2

thanks @Miguel Prz,

i want to use this query but not work:

MySQL("SELECT CONCAT(HOST, ',', e.name), e.severity, location_lat, location_lon
FROM hosts
LEFT JOIN hosts_groups ON (hosts.hostid = hosts_groups.hostid AND hosts.host NOT LIKE '%Template%')
LEFT JOIN hstgrp ON (hstgrp.groupid = hosts_groups.groupid AND hstgrp.name = 'SEKURIT')
LEFT JOIN host_inventory ON (host_inventory.hostid = hosts.hostid)
LEFT JOIN items i ON (i.hostid = hosts.hostid)
INNER JOIN functions f ON (f.itemid = i.itemid)
INNER JOIN triggers t ON (t.triggerid = f.triggerid AND t.value=1)
#INNER JOIN problem pb ON (pb.objectid = t.triggerid)
#INNER JOIN events e ON (e.objectid = t.triggerid)
#GROUP BY hosts.hostid");

result is

DBD::mysql::st execute failed: Unknown column 'e.name' in 'field list' at test4.pl line 33.
DBD::mysql::st execute failed: Unknown column 'e.name' in 'field list' at test4.pl line 33.

do you have an idea?

Answer 3

In your last post there is only one reference to e in the following comment

#INNER JOIN events e ON (e.objectid = t.triggerid)

probably it is better to use syntax INNER JOIN events as e ON (e.objectid = t.triggerid) -- more readable

Answer 4

I do not have a database at hand available right at this moment. The following example should work in theory. I have replaced fetch_array on fetch_hashref the output will provide information about each row

ddddd column=value\tcolumn=value\t...

use strict;
use warnings;

my $query = qq(SELECT * FROM tb_test);

db_query($query);

sub db_query {
    my $query = shift;

    my $count = 1;

    my $dbh = DBI->connect(
                    "DBI:mysql:database=database;host=ip",
                    "login", 'password',
                    {'RaiseError' => 1}
              );

    my $sth = $dbh->prepare($query);

    $sth->execute();

    while ( my $row = $sth->fetchrow_hashref() ) {

            print "%5d ", $count++; # rows count

            while( my($k,$v) = each %$row ) { print "%s=%s\t",$k,$v; }

            print "\n"; # we done with current row
    }

    $sth->finish;
    $dbh->disconnect;
}

You need look into DBI documentation to get full understanding how it works.