Viewing

[Kiko]

Hey,

I left this program alone for a while and now i'm working on
it again.  I'm trying to view the first 100 records from a
database and then display the next 100 and so on.  I'm able
to display the first 100 but i don't know how to show the
next 100.

This is the section of my program that's supposed to do this:


my ($row)=0;
my ($count)=0;
my ($min)=0;
my ($max)=$min+100;

while ($db->FetchRow()) {
    
    if(($row>=$min)&&($row<$max)) {

    my (%dbrow) = $db->DataHash();
    
    $dbrow{'details'}=substr($dbrow{'details'},0,50);

    print<<HERE_HTML_ROW;
        <td bgcolor="$recordbg"><font face="arial" size="1">$dbrow{'la
+stname'},&nbsp;$dbrow{'firstname'}&nbsp;</font>&nbsp;</td>
        <td bgcolor="$recordbg"><font face="arial" size="1">$dbrow{'of
+ficephonenumber'}&nbsp;</font>&nbsp;</td>
        <td bgcolor="$recordbg"><font face="arial" size="1">$dbrow{'de
+scription'}&nbsp;</font>&nbsp;</td>
        <td bgcolor="$recordbg"><font face="arial" size="1">$company_t
+ype&nbsp;</font>&nbsp;</td>
        <td bgcolor="$recordbg"><font face="arial" size="1">$dbrow{'co
+mpany_name'}&nbsp;</font>&nbsp;</td>
        <td bgcolor="$recordbg"><font face="arial" size="1">$dbrow{'de
+tails'}&nbsp;</font>&nbsp;</td>        
HERE_HTML_ROW

    print "\n</tr>\n";
    
    }
    
    $row++;
    $count++;
}

print "\n</table>\n";

my ($visible);

if ($count>=$max){
    $visible=$max;
} else {
    $visible=$count;
}


print<<HERE_HTML;

<BR><font size="2" face="helvetica"><B>1-$visible of $count records di
+splayed</B></font>

HERE_HTML

# This is the part that's not working because i don't think
# that i can do this, please help.

if ($row>$max) {
    print "<font size=2 face=helvetica><a href=\"$ENV{'SCRIPT_NAME'}?$
+ENV{'QUERY_STRING'}&min=100\">Next 100</a></font>\n";
}


Thanks,
Kiko

[Kiko]

The title for this post should have been:

Viewing the first 100 records, then the next 100.

Sorry about that.

[merlyn]

Since you re-started working on this, did you read my column on "giving more" yet? I think I posted that last time, but here it is again!

-- Randal L. Schwartz, Perl hacker

[Kiko]

Is there anohter way to go about this other than using
session ids?

[merlyn]

You have to have some way to correlate one hit with the next. The easiest way is with a session ID that you hold in a hidden field, mangled URL, cookie, basic-auth, or mangled hostname.

-- Randal L. Schwartz, Perl hacker

[Speedfreak]

Hejsan

This was asked before and a good answer was given but I cant remember the author so you'll have to search it.

The proposed solutions was how I would of done it - do it via SQL.

You can use the LIMIT keyword to show a subset of the data returned. For example:

SELECT * FROM mydata LIMIT 100,100;

Here, it tells it to show from the 100th record (1st number) and only 100 records (2nd).

I would approach it by making your "next" link append the next number for limit. Pseudo code may look something like:

my $blocksize = 100;
my $limit = 1 + param("limit");     #get the value from the query stri
+ng

my $sql = "SELECT * FROM data LIMIT $limit,$blocksize;"

Then your next and back buttons may have links like:

showdata.pl?limit=200
showdate.pl?limit=0

Add garnish as desired...

- Jed