按ID重命名文件名

Question

i am trying to rename an image file and save the file location in database. i am having problem problem with it, as i want to name the file as the id of the table row i am inserting in. after uploading and inserting i want to see my table as like this:

----------------------------------------
| id | name | category | image         |
----------------------------------------
| 1  | foo  | category | uploads/1.jpg |
----------------------------------------

the id field is auto incremented. here is my code for it:

function service()
{
    $con=$this->do_upload();
    $id=mysql_insert_id();
    $data=array(
        'name'=>$this->input->post('name'),
        'category'=>$this->input->post('category'),
        'image'=>'uploads/'.$id.$con['file_ext'];
     );
    $query=$this->db->insert('table',$data);
    return $query;
}

this is not the correct way and as assumed the file is not saved in the database as wanted.instead of saving it as 'uploads/1.jpg' it is saved as 'uploads/0.jpg'.
can any one provide me the right convention to do it? n.b. i am using codeigniter 2.1.0 and mySQL database.

Answer 1

You cannot access id with mysql_insert_id without calling mysql query before. You have to insert new record and then update it. with new filename.

Edit:

When I was uploading images/other files to the server, I was always renaming them with some random hash. So files had unique hash name on filesystem and in mysql row there was set just this hash to associate db row with file.

So before inserting new record into db, generate some random string with checking if file with this name already exists:

$filename = '';
do {
  $filename = substr(md5(uniqid(rand(), true)), 0, 8);
} while ( !file_exists('uploads/'.$filename) );

Do it in do_upload method and let it to return file's name in $con array.