#!/usr/bin/perl -W

use DBI;
use Text::CSV_XS;

# GLOBALS
@id = "";
$dbname = "";
$user = "";

# MAIN MENU
# Don't allow duplicated arguments and blank/undef arguments
# except for id (in this case blank/undef id means all ids)
foreach my $arg (@ARGV)
{
    if ($arg eq '-h' || $arg eq '--help')
    {
        die "Script usage manual here\n";
        exit;
    }
    
    if ($arg =~ /^(\w+)$/)
    {
        die "Error: Multiple databases: $dbname and $arg." if $dbname;
        
        $dbname = $1 ; next;
    }
    
    if ($arg =~ /^--?u(\w+)$/)
    {
        die "Error: Multiple users $user and $arg." if $user;
        
        $user = $1 ; next;
    }
    
    if ($arg =~ /^--?id(\d+)$/)
    {
        die "Error: Multiple ids specified: -id$id[0] and $arg.\n" if $id[0];

        $id[0] = $1 ; next;
    }
    elsif ($arg =~ /^--?id(\S+|)$/)
    {
        die "Error id format, use -id<integer>\n";
    }    
}

die "No database, type <dbname>\n" unless $dbname;
die "No username, use -u<username>\n" unless $user;


# DBI CONNECTION
my $dbh = get_dbh();

# EXEC
if ($id[0] eq "")
{   
    my $sql = "SELECT DISTINCT id from mytable
             WHERE active = ?";
    @id = map{ $_->[0] } $dbh->selectall_array($sql,undef,'no');
}

for my $id (@id)
{
  my @query =
  (
    ["SELECT id FROM mytable     WHERE id=? AND salary >= 1","csvfile1_$id.csv"],
    ["SELECT name FROM mytable   WHERE id=? AND salary >= 1","csvfile2_$id.csv"],
    ["SELECT salary FROM mytable WHERE id=? AND salary >= 1","csvfile3_$id.csv"],
    ["SELECT dept FROM mytable   WHERE id=? AND salary >= 1","csvfile4_$id.csv"],
  );

  for (@query)
  {
    run_query(@$_,$id);
  }
}

# SUBROUTINES
sub get_dbh
{
    my($dbh) = DBI->connect("dbi:IngresII:$dbname","$user","")
        or die "Could not connect to database $dbname\n";
    
    return $dbh;
}

sub run_query 
{
    my ($sql, $csvfile, $id) = @_;
    print "Running $sql for $id\n";
    
    open my $fh, '>', $csvfile or die "Could not open $csvfile: $!";

    my $csv = Text::CSV_XS->new ({ binary => 1, eol => "\n" });
    my $sth = $dbh->prepare ($sql); 
    $sth->execute($id);
    $csv->print($fh, $sth->{NAME_lc});
    my $count = 1;
    
    while (my $row = $sth->fetchrow_arrayref)
    {
        $csv->print($fh, $row);
        ++$count;
    }
    
    close $fh;
    
    print "ID: $id, $count lines dumped to $csvfile\n";
}