Description:
------------
I am using mysql 5.0.27.

There is a table that has a unique index on it. When inserting a new row that would violate the uniqueness using a prepared statement no errors/exceptions are raised. When looking at the query log the statement is prepared but no executions queries. Should there not be an exception raised for the error?

I did a google search and searched the bug database but did not find an existing issue.

Reproduce code:
---------------
CREATE TABLE `docs_classification` (
  `classification_id` smallint(6) NOT NULL auto_increment,
  `name` varchar(100) NOT NULL,
  `description` varchar(255) NOT NULL,
  `short_name` char(3) NOT NULL,
  `bit_value` int(11) NOT NULL,
  PRIMARY KEY  (`classification_id`),
  UNIQUE KEY `bit_value` (`bit_value`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=10 ;

//////////
First Run

array('test1', 'test1test1', 'TS1', '1'),
array('test2', 'test2test2', 'TS2', '2'),
array('test3', 'test3test3', 'TS3', '4')
);

$m = new mysqli('localhost', 'dbuser', '','dbname');
$sql = 'INSERT INTO dbtable '
' (classification_id, name, description, short_name, bit_value) '.
' VALUES (NULL, ?, ?, ?, ?)';

$stmt = $m->prepare($sql);

foreach ($a as $b)
{
	$stmt->bind_param('ssss', $b[0], $b[1], $b[2], $b[3]);
	$stmt->execute();
}

///////
Then repeat above code and no errors are raised.

Expected result:
----------------
Expected to be notified of the duplicate entry error in the bit_value field when re-running the code.

Actual result:
--------------
No errors or indication of any errors.

In the query log it shows the sql being prepared but no Execute commands.