PDO inserts an id as 0 for some reason - php

Question

So I wrote this method, for my chrome plugin (which does an ajax request to run this method), and when it runs, file_put_contents shows an id of what ever was inserted, but then when it gets to the insert ignore into songs, it puts in 0 for the artist_id. I have no idea why... Can someone help my find the part where I am going wrong?
<?php
public function saveLyrics($artist, $title, $lyric){
$this->db->query("insert ignore into artists (artist_name) value (:artist)", array("artist" => $artist));
$artist_id = (int)$this->db->insertID();
file_put_contents(__DIR__ . "/../process/page", "artist id: $artist_id");
//return;
if($artist_id == 0){
$artist_id = (int)$this->db->getOne("select artist_id from artists where artist_name = :artist", array("artist" => $artist));
}
if($artist_id == 0){
return false;
}
$this->db->query("insert ignore into songs (artist_id, song_name) values (:aid, :title)", array("aid" => $artist_id, "title" => $title));
$song_id = (int)$this->db->insertID();
if($song_id == 0){
$song_id = (int)$this->db->getOne("select song_id from songs where artist_id = aid and song_name = :title", array("aid" => $artist_id, "title" => $title));
}
}
PDO Wrapper:
<?php
/**
* #property PDO $pdo Description
* #property PDOStatement $sql Description
*/
class DB{
protected $sql = null;
protected $pdo = null;
public function connect(){
$this->pdo = new PDO("mysql:dbname=envne;host=xxx", "xxx", "xxx");
}
public function query($query, $params = array()){
if($this->pdo === null){
$this->connect();
}
$this->sql = $this->pdo->prepare($query);
foreach($params as $key => $value){
$this->sql->bindParam($key, $value);
}
$this->sql->execute();
if(!$this->sql)
return false;
return true;
}
public function insertID(){
return (int)$this->pdo->lastInsertId();
}
public function getAll($query, $params = array()){
$this->query($query, $params);
return $this->sql->fetchAll();
}
public function getOne($query, $params = array()){
$this->query($query, $params);
return $this->sql->fetchColumn();
}
}
Artists:
mysql> describe artists;
+-------------+------------------+------+-----+-------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------------+------+-----+-------------------+----------------+
| artist_id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| artist_name | char(50) | YES | UNI | NULL | |
| add_date | timestamp | YES | | CURRENT_TIMESTAMP | |
+-------------+------------------+------+-----+-------------------+----------------+
3 rows in set (0.00 sec)
Songs:
mysql> describe songs;
+------------+------------------+------+-----+-------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+------------------+------+-----+-------------------+----------------+
| song_id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| artist_id | int(11) unsigned | YES | MUL | NULL | |
| album_id | int(11) | YES | MUL | NULL | |
| song_name | char(50) | YES | | NULL | |
| track_id | int(11) | YES | | NULL | |
| date_added | timestamp | NO | | CURRENT_TIMESTAMP | |
+------------+------------------+------+-----+-------------------+----------------+
6 rows in set (0.01 sec)

Answer 1

I just decided to put the Id directly into the query, and that works.
$artist_id = (int)$this->db->insertID();
$this->db->query("insert ignore into songs (artist_id, song_name) values ($artist_id, :title)", array("title" => $title));
Another way that works is using a question mark instead
$artist_id = (int)$this->db->insertID();
$this->db->query("insert ignore into songs (artist_id, song_name) values (?, ?)", array($artist_id, $title));

Answer 2

I just had the same problem : new inserted items get an id of 0 even though the ID field is set to AUTO_INCRIMENT.
The solution I found is very similar to yours. Using your code this is what we get :
$this->db->query("insert ignore into songs (artist_id, song_name) values (LAST_INSERT_ID(), :title)", array("title" => $title));
As you can see, I replaced $artist_id = (int)$this->db->insertID(); and $artist_id with SQL function LAST_INSERT_ID().
I hope this can help someone someday :)

Answer 3

You're placeholders are incorrectly defined: (You're missing the colons)
I would do something like this:
public function saveLyrics($artist, $title, $lyric){
$this->db->query("insert ignore into artists (artist_name) value (:artist)", array(":artist" => $artist));
$artist_id = (int)$this->db->insertID();
file_put_contents(__DIR__ . "/../process/page", "artist id: $artist_id");
//return;
if($artist_id == 0){
$artist_id = (int)$this->db->getOne("select artist_id from artists where artist_name = :artist", array(":artist" => $artist));
return false;
}
$this->db->query("insert ignore into songs (artist_id, song_name) values (:aid, :title)", array(":aid"=>$artist_id, ":title"=>$title));
$song_id = (int)$this->db->insertID();
if($song_id == 0){
$song_id = (int)$this->db->getOne("select song_id from songs where artist_id = :aid and song_name = :title", array(":aid"=>$artist_id, ":title"=>$title));
}
}
Taking a look at your PDO-wrapper you have this code:
if(!$this->sql)
return false;
Because of this you would never notice an actual error. I guess the error is about the placeholder in this case.
(If $this->db->query("insert ignore into songs (... fails $song_id would just be false if there is an error when executing the query).
Use exceptions instead and catch the errors, that would be better.
I also noticed that:
$song_id = (int)$this->db->insertID();
would cast the value twice, first in above code and then in the actual function insertID() in the PDO-Wrapper. Maybe this is an issue also to consider.