Mysterious duplicate entries in SQLite table when using INSERT - sql

Question

Before I used PDO and it worked fine but I had problems with inserting pictures. Now I switched to SQLite3 and the pictures are now stored correctly. But I'm experiencing a strange problem with SQLite3. Every INSERT INTO command is done twice. And this only concerns INSERT, because I had no problems with UPDATE or DELETE.
This is my test script
<?php
require_once('class.DatabaseQuery.php');
$db = new DatabaseQuery();
$sql = 'INSERT INTO Bezeichnungen(Bezeichnung_de,Bezeichnung_en,Bezeichnung_it) values("test","test","test");';
$result = $db->ExecuteQuery($sql);
echo "<pre>";
print_r($result);
echo "</pre>";
?>
This is my database class:
<?php
class DatabaseQuery {
private $_handle;
public function ExecuteQuery($sql, $params = array())
{
echo $sql;
echo "<strong>execute Query params</strong><pre>";
print_r ($params);
echo "</pre>";
echo count($params);
// make new connection if not available
if($this->_handle == null)
$this->Connect();
// make prepared statement
$query = $this->_handle->prepare($sql);
// add values to prepared statement depending on type
foreach($params as $key => $value)
{
if(is_int($value)){
$query->bindValue(':'.$key, $value, SQLITE3_INTEGER);
}else if(is_null($value)){
$query->bindValue(':'.$key, $value, SQLITE3_NULL);
}else if(strpos($value, "home/www/") !== false){
$value=file_get_contents($value);
$query->bindValue(':'.$key, $value, SQLITE3_BLOB);
$value="X'" . strtoupper(bin2hex($value));
}else{
$query->bindValue(':'.$key, $value, SQLITE3_TEXT);
}
}
$result = $query->execute();
// get all results
while($row = $result->fetchArray(SQLITE3_ASSOC)){
$res[] = $row;
}
//var_dump($x);
return $res;
}
public function Connect()
{
$this->_handle = new SQLite3("database.db");
}
public function Disconnect()
{
// close database connection
$this->_handle->close();
}
}
?>
And this is the create statement of my table
CREATE TABLE Bezeichnungen
(
_id INTEGER PRIMARY KEY,
Bezeichnung_de TEXT,
Bezeichnung_en TEXT,
Bezeichnung_it TEXT
)
Either I'm using SQLite3 the wrong way or the used library has a bug.
I'm using PHP 5.3.9, SQLite3 module version 0.7-dev and SQLite Library 3.7.7.1.
Perhaps someone can test my code on his plattform and tells me if he has the same problem.