无法在数据库$ count！= 1中写入数据

I am currently working on a project but can't continue due a error that keeps on coming and I don't know why but perhaps you guys would know. When I fill in my form and want to insert my data in the database I get the error feedback account creation failed. Which is below.

so here is the code:

    // write new users data into database
        $sql = "INSERT INTO users (user_name, user_password_hash, user_email, user_creation_timestamp, user_activation_hash, user_provider_type, user_persnaam, user_bondsnummer, user_telefoonnummer, user_leeftijd, user_enkelsterkte, user_dubbelsterkte, user_geslacht)
                VALUES (:user_name, :user_password_hash, :user_email, :user_creation_timestamp, :user_activation_hash, :user_provider_type, :user_persnaam, :user_bondsnummer, :user_telefoonnummer, :user_leeftijd, :user_dubbelsterkte, :user_enkelsterkte, :user_geslacht)";
        $query = $this->db->prepare($sql);
        $query->execute(array(':user_name' => $user_name,
                              ':user_password_hash' => $user_password_hash,
                              ':user_email' => $user_email,
                              ':user_persnaam' => $user_persnaam,
                              ':user_bondsnummer' => $user_bondsnummer,
                              ":user_telefoonnummer" => $user_telefoonnummer,
                              ":user_enkelsterkte" => $user_enkelsterkte,
                              ":user_dubbelsterkte" => $user_dubbelsterkte,
                              ":user_leeftijd" => $user_leeftijd,
                              ':user_geslacht' => $user_geslacht,
                              ':user_creation_timestamp' => $user_creation_timestamp,
                              ':user_activation_hash' => $user_activation_hash,                                  
                              ':user_provider_type' => 'DEFAULT'));
        $count =  $query->rowCount();
        if ($count != 1) {
            $_SESSION["feedback_negative"][] = FEEDBACK_ACCOUNT_CREATION_FAILED;
            return false;
        }

the problem seems to be that I can't write anything into my database but I am sure that I can connect and update everything but not write. So the problem isn't with the connection to the database. I think it has something to do with the rowcount but maybe you guys know what's wrong. The double quotes aren't the problem I've checked that already.

Thanks in advance

I don't know if this will be helpful, @fred gave you a few clue, and you said you are sure the connection is good. Here is what I caught:

INSERT INTO users 
            (user_name, 
             user_password_hash, 
             user_email, 
             user_creation_timestamp, 
             user_activation_hash, 
             user_provider_type, 
             user_persnaam, 
             user_bondsnummer, 
             user_telefoonnummer, 
             user_leeftijd, 
             user_enkelsterkte,  /* here user_enkelsterkte is first */
             user_dubbelsterkte, /* here user_dubbelsterkte is second */
             user_geslacht) 
VALUES      (:user_name, 
             :user_password_hash, 
             :user_email, 
             :user_creation_timestamp, 
             :user_activation_hash, 
             :user_provider_type, 
             :user_persnaam, 
             :user_bondsnummer, 
             :user_telefoonnummer, 
             :user_leeftijd, 
             :user_dubbelsterkte, /* here user_dubbelsterkte is first */
             :user_enkelsterkte,  /* here user_enkelsterkte is second */
             :user_geslacht)

If there is a column type or length mismatch it will fail.

Here is a better way to write your code would be:

$this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
if ($query = $this->db->prepare($sql)) { 
  // put code here
}else{
    echo "
PDO::errorInfo():
"; 
    print_r($this->db->errorInfo()); 
}

You can do error checking on connection, prepare() or execute().

Now you should find out if you get an error.