Fetching DB using a While loop.

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks!
I am fetching a database but I want to use a "WHILE" loop instead of a "FOR" loop, how could I do this here, here is a sample code to demonstrate what I am trying to do:


my $sql = "select name,address,phone,email from my table where name='m
+ary'";
my $allnames= $dbh->exec_select( $sql ) or die "Couldn't execute state
+ment: $dbh->errstr";;


      
if(@$allnames)  { 

      for (my $i = 0; $i < @$allnames; $i++)  
       {


         my $allname = $allnames->[$i]{ 'name' } || '';
     my $alladdress = $allnames->[$i]{ 'address' } || '';
     my $allphone= $allnames->[$i]{ 'phone' } || '';
     my $allemail = $allnames->[$i]{ 'email' } || '';
        
          
         $AoH{ alldata } = $allname."&nbsp;".$alladdress."&nbsp;".$all
+phone ."&nbsp;".$allemail;  

}
[download]

Thanks!

Comment on Fetching DB using a While loop. Download Code

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Re: Fetching DB using a While loop. by almut (Canon) on Apr 20, 2010 at 18:30 UTC
I want to use a "WHILE" loop instead of a "FOR" loop `my $i = 0; while ($i < @$allnames) { .... $i++; }` [download] instead of `for (my $i = 0; $i < @$allnames; $i++) { .... }` [download] But why...? — Maybe you rather want something like `for my $elem (@$allnames) { my $allname = $elem->{name} \|\| ''; my $alladdress = $elem->{address} \|\| ''; ... }` [download]	[reply] [d/l] [select]
Re: Fetching DB using a While loop. by leighsharpe (Monk) on Apr 21, 2010 at 00:33 UTC
`my $sql = "select name,address,phone,email from my table where name='m +ary'"; my $sth=$dbh->prepare($sql) or die "Couldn't prepare statement handle: + ".$dbh->errstr(); my $count=$sth->execute() or die "Couldn't execute statement:".$dbh->e +rrstr(); while (my @row=$sth->fetchrow_array()) { $AoH{ alldata } = join (' ', @row); } $sth->finish();` [download] But what is 'alldata'? The row inside the loop will continually overwrite its own results, I suspect you actually want something more like: `push(@some_array, join(' ', @row));` [download] Oh, and of course, you'll be using placeholders in the real thing, right? `my $sql="select name,address,phone,email from my table where name=?"; my $sth=$dbh->prepare($sql) or die "Couldn't prepare statement handle: + ".$dbh->errstr(); my $count=$sth->execute('mary') or die "Couldn't execute statement:".$ +dbh->errstr();` [download]	[reply] [d/l] [select]