Name the database "upload". The database contains the table 'file_manager', which manages file information. The SQL statement for creating the table:


CREATE TABLE file_manager (
file_name varchar(50) default NULL, 

file_type varchar(20) NOT NULL default '', 
file_size varchar(20) NOT 
NULL default '', 
file_modified varchar(20) NOT NULL default '', 

file_parent_id mediumint(9) default NULL, 
file_image_name varchar(50) 
default NULL, 
 
KEY file_name (file_name), 
KEY file_image_name (file_image_name)
) 
TYPE=MyISAM; 



File Management
I've written two programs to manage this file version. The first uploads the file (file_upload_manager.php), the second displays the file (file_upload_manager.php). The source code is tested on a Windows system.

NOTE:  Linux users, please change the folder path accordingly.

File Upload Manager:
This program displays a menu to select the file in your system, a check box and an Upload button. Once the user clicks the upload button, the program checks the file for existence, and undergoes a series of tests as described in the plan.

Now let's look at the code snippets used in the program.


$dir_path Variable:



This variable is the destination folder path.


$dir_path= "C:apachehtdocsfilemanager";



This path is given for Windows-based systems. Please change your destination folder accordingly.


Get_New_File_Name() Function:



This function is called from the main program when the program encounters files that exist and show a difference in size, date or time. This function will generate a new file name and return to the main function.


function Get_New_FIle_Name($file_name)
{
  
$sqlQuery="SELECT  file_image_name FROM file_manager WHERE  file_name 
LIKE '$file_name%' AND  file_parent_id=1";
 
  $fResult=mysql_query($sqlQuery);
  $Last_Version=0;
  
$ver=0;
 
  if(mysql_num_rows($fResult)){
      
while($fRow=mysql_fetch_array($fResult)){          

 
list($junk,$ver)=explode("_VERSION",$fRow['file_image_name']);
         
list($ver,$extn)=explode(".",$ver);
         
$Last_Version = $Last_Version > $ver ? $Last_Version : 
 
$ver;
       }
  
}else{
      $new_file_name 
=$file_name."_VERSION".++$Last_Version;
      return 
$new_file_name;
  }
 
  if($Last_Version !=0){
      
$new_file_name=$file_name."_VERSION".++$Last_Version;
      
return $new_file_name;
  }
}



The sql query in the beginning of the function will fetch file names of previous versions. If the sql query returns record sets, it means the file has previous versions. The while loop is executed to store the generated version number, and the value obtained is stored in $Last_Version. Otherwise, the new file name will be generated as file-name_VERSION1.

The next if statement checks for $Last_Version != 0, if true, $Last_Version is incremented by 1 and a new file name is assigned.

The return statement will return a new file name generated to the called statement.