my $sql = 'SELECT * FROM table WHERE column IN (' . ( join ',', map { 
+"'$_'" } @array ) . ')';
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That could get you into trouble with quote problems in @array values or worse sql-injection. At the very least you should use the DBI quote method:

my $sql = 'SELECT * FROM table WHERE column IN (' .
   ( join ',', map { $dbi->quote($_) } @array ) . ')';
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Or better, use placeholders

my $sql = 'SELECT * FROM table WHERE column IN (' .
   '?' . (',?' x $#array) . ')';
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#!/usr/bin/perl

use strict;
use DBI;

my $dbh = DBI->connect( ... );

my @val1_set = qw/foo bar baz quz/;

my $sth = $dbh->prepare("select val1,val2,val3 from atable where val1=
+?");
my @result_set;

for my $val ( @val1_set ) {
    $sth->execute( $val );
    my $result = $sth->fetchall_arrayref;
    push @result_set, $result;
}
for my $i ( 0 .. $#val1_set ) {
    print "Results for val1=$val1_set[$i]:\n";
    if ( ref( $result_set[$i] ) ne "ARRAY" or
         @{$result_set[$i]} == 0 ) {
        print "__EMPTY_SET__\n\n"
    }
    else {
        for my $row ( @{$result_set[$i]} ) {
            print join("\t", @$row ),"\n"
        }
        print "\n";
    }
}
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(update: And in this case, since the result set is an array that is built up over some number of execute calls, you are starting with an AoAoA, so the sample code uses $i to iterate over the top-level array.)

Thanks, this is very helpful. What was least clear for me is whether, if I have to loop through the array anyway, I should loop through the select and in the same loop print the values, whether I should wait until I've gotten the values and then print them all, or whether there was something like execute_array that would handle them all at the same time. I believe I read that execute_array is not for SELECT statements, though, even though I can't figure out where I'd have read that.

Would it be something like this?

$sqlfmt = "SELECT val1,val2,val3 where val1 = %d";

foreach (@values) {
  $sql = sprintf($sqlfmt, $_);
}
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This is the wrong way!

The right way is to do it like this:

foreach my $value (@values) {
    
    $sth->execute($value);
}
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