my $proj_id_sth = $dbh->prepare( "select project_name,project_id from projects" );
$proj_id_sth->execute;

my %proj_name_id;
while ( my $row = $proj_id_sth->fetchrow_arrayref ) {
    my ( $pr_name, $pr_id ) = @$row;
    $proj_name_id{$pr_name} = $pr_id;
}