Re: MySQL hashes with same key

[NetWallah]

Your code and comments are confusing. If you want to obtain comments for a known mac address, why dont you use the database to do the appropriate query:

"select  comment 
from     arp.filter 
where    operation = 'filter' AND MAC='$mac_t'"

Also, Using fetchrow_arrayref instead of fetchrow_hashref will not make any difference to the resulting rows, as you seem to think it might.

[mje]

He wasn't fetching using fetchrow_arrayref or fetchrow_hashref he was fetching with selectall_hashref and it does make a difference:

SQL> create table mje(mac varchar(10), comment varchar(10));
SQLRowCount returns -1
SQL> insert into mje values('1226', 'comment1');
SQLRowCount returns 1
SQL> insert into mje values('1226', 'comment2');
SQLRowCount returns 1
SQL> insert into mje values('1226', 'comment3');
SQLRowCount returns 1
SQL> select * from mje;
+-----------+-----------+
| mac       | comment   |
+-----------+-----------+
| 1226      | comment1  |
| 1226      | comment2  |
| 1226      | comment3  |
+-----------+-----------+
SQLRowCount returns -1
3 rows fetched
SQL>

perl -le 'use DBI; my $h = DBI->connect;nect; my $r = $h->selectall_ha
+shref(q/select * from mje/, "mac"); use Data::Dumper; print Dumper($r
+);'
$VAR1 = {
          '1226' => {
                      'comment' => 'comment3',
                      'mac' => '1226'
                    }
        };

perl -le 'use DBI; my $h = DBI->connect;nect; my $r = $h->selectall_ar
+rayref(q/select * from mje/); use Data::Dumper; print Dumper($r);'
$VAR1 = [
          [
            '1226',
            'comment1'
          ],
          [
            '1226',
            'comment2'
          ],
          [
            '1226',
            'comment3'
          ]
        ];

If you use selectall_hashref or fetchall_hashref you need to provide a key column and if you have multiple rows where that key column has the same value you will lose some rows.

[NetWallah]

Thanks - I had missed the subtlities of the second parameter to 'selectall_hashref'.

However - my recommendation to use the database query to select comments for a mac stands, and answers the the questions he persists in posing.

[jcrush]

Hi, I was just trying to reduce repeated access to the database.
I thought I could save it to a hash locally, and process the requested information from the hash.
Thank you.

[Anonymous Monk]

So, don't do that. It's the wrong thing to do in this case. :-/

[jcrush]

Thanks for the reply.
I was using my smartphone, at night. I cleared up the wording, I hope.
I would like to print out a list of comments for one address. If I search for mac aaaa.aaaa.aaaa.aaaa

Printout

Mac: aaaa.aaaa.aaaa.aaaa
Comments: filtered for virus 
filtered by dmca 
filtered for excessive bandwidth 
filter on spoofed mac

Thanks again.