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Re^3: DBI Row Limiting

by zdog (Priest)
on Sep 14, 2004 at 16:59 UTC ( #390910=note: print w/ replies, xml ) Need Help??


in reply to Re^2: DBI Row Limiting
in thread DBI Row Limiting

There in fact are method(s) that limit the number of results you get. They're called fetchrow_*(). They limit the number of results to one row so you can control however many you actually obtain. Straight out of the DBI documentation:

$sth = $dbh->prepare("SELECT foo, bar FROM table WHERE baz=?"); $sth->execute( $baz ); while ( @row = $sth->fetchrow_array ) { print "@row\n"; }

Now you can transform this a little to suit your needs like merlyn was talking about:

my $LIMIT = 30; my $sth = $dbh->prepare("SELECT foo, bar FROM table WHERE baz=?"); $sth->execute( $baz ); my ( @rows, @row ); for ( 1 .. $LIMIT ) { last unless ( @row = $sth->fetchrow_array ); push @rows, [ @row ]; } #do stuff with @rows

This code is untested but you get the general idea. There are other types of fetchrow_*() methods that you can take a look at. Read the DBI documentation.

Update: You can also take a look at the fetchall_arrayref() method which appears to take a $max_rows parameter.

Zenon Zabinski | zdog | zdog@perlmonk.org


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