Inserting data into database with pdo prepared statment

Question

Inserting data into database with pdo prepared statment, doesnt work for me:

I use this function:

    public function get_number_of_matches(){
     $stmt = $this->pdo->prepare("INSERT INTO `words`( `word_name`, `word_count`, `search_id`) VALUES (:word, :count,:searchID)");
       $stmt->bindParam(':word', $word);
       $stmt->bindParam(':count', $count);
       $stmt->bindParam(':searchID', $search_id);
   for($i=0;$i<count($this->words);$i++){
     if(preg_match_all('/'.$this->words[$i].'/i', $this->text,$matches)){
       $count=count($matches[0]);
       $word=$this->words[$i];
        $search_id=1;
       $stmt->execute();
         break;
    }   

   }
    return 0;
}

Basically, I try to loop over the values and put them into the database.. no error is given.. nothing goes into the database ..why?

This is how I connect to the database:

 class DBConnection {
    public static $connect;

    public static function connect(){

        if(!isset(self::$connect)){
            try{
              self::$connect=new PDO('mysql:host=localhost;dbname=tweeter', 'root', '');
            }catch(Exception $ex){
               echo $ex->getMessage();   
            }
        }
        return self::$connect;
    }
}

UPDATE Also..see here:

I do the same thing with a different query..but when I try to put object properties inside a variable I get an error:

$tweet= $tweet->tweet ; $user=$tweet->tweeter_name; $link= $tweet->link;

Those variables go into a query:

       $pdo=  DBConnection::connect();
    $stmt = $pdo->prepare("INSERT INTO `tweets`( `tweet`, `tweeter_name`, `link`, `date`, `search_id`) VALUES (:tweet, :tweeter_name, :link, :date, :search_id)");
      $stmt->bindParam(':tweet', $tweet);
       $stmt->bindParam(':tweeter_name', $user);
       $stmt->bindParam(':link', $link);
       $stmt->bindParam(':date', $date);
       $stmt->bindParam(':search_id', $search_id);

I get errors like this:

Notice: Trying to get property of non-object in C:\\xampp\\htdocs\\Twitter\\demo.php on line 36

Notice: Trying to get property of non-object in C:\\xampp\\htdocs\\Twitter\\demo.php on line 37

Notice: Trying to get property of non-object in C:\\xampp\\htdocs\\Twitter\\demo.php on line 38

I can print the properties..but when allocating them to those binded variables..the above errors crop up

I get also this:

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'tweeter_name' cannot be null' in C:\\xampp\\htdocs\\Twitter\\demo.php:40 Stack trace: #0 C:\\xampp\\htdocs\\Twitter\\demo.php(40): PDOStatement->execute() #1 {main} thrown in C:\\xampp\\htdocs\\Twitter\\demo.php on line 40

I checked instead like this:

    $tweet= "111111"; // $tweet->tweet ;
        $user= "22222222"; // $tweet->tweeter_name;
        $link= "3333333";  // $tweet->link;
        $date= "444444";

and it worked..for some reason it hates those object properties ?!?

This should go as input:

RT @OrganicLiveFood: Scientists Warn #EPA Over #Monsanto's #GMO Crop Failures & Dangers #prop37 #labelGMO #yeson37 http://t.co/2XhuVxO8 Doumastic TweetCaster for iOS Mon, 19 Nov 2012 20:40:55 +0000 RT @OrganicLiveFood: Scientists Warn #EPA Over #Monsanto's #GMO Crop Failures & Dangers #prop37 #labelGMO #yeson37 http://t.co/2XhuVxO8

But it doesnt...?!?

Answer 1

Add self::$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); right after connecting.

It would make sure PDO will throw PDOExceptions on every error, making them very easy to see. The error would then outline exactly what's wrong.

Answer 2

Check the return value from $stmt->execute() , if there was a problem it will return false and you should check $stmt->errorInfo() for details.

Or else use the ERRMODE_EXCEPTION that @Madara Uchiha suggests, but if you're not already handling exceptions in your application, this can be hard to adapt to.

---

Re: your update.

You should check error status from both PDO::prepare() and PDOStatement::execute() every time you call them. The error about "Trying to get property of non-object" likely means that $stmt is actually the boolean value false instead of a valid PDOStatement object. Your call to $stmt->bindParam() fails because false is not an object, so it cannot have a bindParam() method.

In my opinion it's much easier to pass parameters by value instead of binding variables by reference. Here's an example of both error-checking and parameters by value:

$pdo =  DBConnection::connect();

$sql = "INSERT INTO `tweets`( `tweet`, `tweeter_name`, `link`, `date`, `search_id`) 
    VALUES (:tweet, :tweeter_name, :link, :date, :search_id)";

if (($stmt = $pdo->prepare($sql)) === false) {
    die(print_r($pdo->errorInfo(), true));
}

$params = array(
    ':tweet'        => $tweet,
    ':tweeter_name' => $user,
    ':link'         => $link,
    ':date'         => $date,
    ':search_id'    => $search_id
);

if (($status = $stmt->execute($params) === false) {
    die(print_r($stmt->errorInfo(), true));
}

The error "Column 'tweeter_name' cannot be null'" that you saw in the exception means that your tweeter_name column is declared NOT NULL, but your $user variable had no value when you bound it to the :tweeter_name parameter.