here is a simple example:
mysql> show create table t1 ;
+-------+--------------------------------------------+
| Table | Create Table                                                
+                                                                 |
+-------+--------------------------------------------+
| t1    | CREATE TABLE `t1` (
  `a` varchar(100) default 'TEST TABLE',
  `b` int(11) default '10'
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+-------+-------------------------------------------+

[download]
This is my test script ph.pl:
#! /usr/bin/perl

use DBI;
use strict ;

my $dsn = "DBI:mysql:database=test;host=localhost";
my $dbh = DBI->connect($dsn, "root", "");

my $sth = $dbh->prepare("INSERT INTO t1 (a,b) VALUES(?,?)") ;

my @a = (undef,undef ) ;
$sth->execute(@a) ;

$dbh->disconnect() ;

[download]
Running this script gives:
mysql> select * from t1 ;
+------+------+
| a    | b    |
+------+------+
|      | NULL |
+------+------+
1 row in set (0.00 sec)

[download]
So there is no NULL for column a!

In reply to Re^2: MySQL: placeholders and NULL values by jeanluca
in thread MySQL: placeholders and NULL values by jeanluca

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