The IN keyword was there since SQL-86 (I believe):

SELECT val1 FROM tbl1 WHERE x IN (11, 22, 33, ...);
[download]

Here's an elaborate example:

useDBIx::Interp;

my $dbx = DBIx::Interp->new($dbh);

my @ary = @{
  $dbx->selectcol_arrayref_i(
    "SELECT val1 FROM tbl1 WHERE",
    { x => \@id },
  )
};
[download]