Insert Blobs in MySql databases with php

I am trying to store an image in the DataBase, for some reason it doesn't seem to work. Here's the structure of my table.

mysql> describe ImageStore;
+---------+----------+------+-----+---------+-------+
| Field   | Type     | Null | Key | Default | Extra |
+---------+----------+------+-----+---------+-------+
| ImageId | int(11)  | NO   | PRI | NULL    |       |
| Image   | longblob | NO   |     | NULL    |       |
+---------+----------+------+-----+---------+-------+
2 rows in set (0.01 sec)

And here is my query which inserts the image or at least thats what it should:

//Store the binary image into the database
                $tmp_img = $this->image['tmp_name'];
                $sql = "INSERT INTO ImageStore(ImageId,Image)               
                VALUES('$this->image_id','file_get_contents($tmp_image)')";
                mysql_query($sql); 

If I print the value of file_get_contents($tmp_image), then there is a tons of data on the screen. But this value doesn't get stored in the database and that is the issue that I'm facing.