my $dbh = do_dbi_connect( $db_type, $db_name, $db_username, $db_password, @_ );

my $sql =<<SQL;
SELECT *
FROM some_table
WHERE
    some_val  = ? OR
    other_val = ?
SQL

# now exec our sql using bind values to get our sth
# these replace our ? placeholders and will be quoted correctly
my $sth = do_sql_sth( $dbh, $sql, $bind_val1, $bind_val2 );
while( my $res = $sth->fetchrow_array() ) {
    # blah
}
$sth->finish

##### STANDARD DATABASE FUNCTIONS #####

# do_dbi_connect( DB_TYPE, DB_NAME, DB_USERNAME, DB_PASSWORD, @OPTIONS )
# connect to the specified DB_TYPE and DB_NAME using the DB_USERNAME and
# DB_PASSOWRD as well as passing any other @OPTIONS
# returns the DBH
sub do_dbi_connect {
    my ( $db_type, $db_name, $db_username, $db_password ) = ( shift, shift, shift, shift );
    my $dbh = DBI->connect("dbi:$db_type:$db_name", $db_username, $db_password ) or die_nice( $DBI::errstr );
  return $dbh;
}

# do_sql( DBH, SQL, BIND_VAL1.....BIND_VALx )
# prepares, executes and closes sth in one call
# typical use for create tables, update tables
sub do_sql {
    my $dbh = shift;
    my $sql = shift;
    my $sth = get_sth( $dbh, $sql );
    $sth->execute(@_) or 
        die_nice( "Could not execute SQL statement\n\n$sql\n" . $sth->errstr() );
    $sth->finish;
}

# do_sql_sth( DBH, SQL, BIND_VAL1.....BIND_VALx )
# as for do_sql but returns the STH
# obviously does not call finish on the STH (so you have to remember)
# typical use for fetchrow_blah
sub do_sql_sth {
    my $dbh = shift;
    my $sql = shift;
    my $sth = get_sth( $dbh, $sql );
    $sth->execute(@_) or 
        die_nice( "Could not execute SQL statement\n\n$sql\n" . $sth->errstr() );
  return $sth;
}

# get_sth( DBH, SQL )
# returns a (cached) STH for the supplied DBH and SQL
sub get_sth {
    my ( $dbh, $sql ) = @_;
    my $sth = $dbh->prepare_cached($sql) or 
        die_nice( "Could not prepare SQL statement\n\n$sql\n" . $dbh->errstr() );
  return $sth;
}

# die nice( ERROR )
# dies with ERROR after printing a valid header and error message to browser
# you may choose to modify this to produce a BS message to the user like
# 'the server can not respond to your request at this time due to routine  maintenance'
# or some such rubbish. just make sure you get to see the ERROR!

sub die_nice { 
    print "Content-type: text/html\n\n$_[0]"; 
    die $_[0] 
}