如何从函数中获取正确的最大ID和最小ID？

Question

I had a large table with 3 million rows before, but I split it to 6 tables 500.000 rows each, now I'm trying to connect them, but I want to read 1 table by 1 not all 6 tables at the same time, I'm trying to use my website pagination to select which table needs to be read and with which max id and min id.

I made this function:

  $content['data']['max_table']  = 6;
  $content['data']['min_table']  = 1;
  $content['data']['limit_page'] = 100;

  function Tables( $start_num, $end_num ) {
   global $content;

   if($end_num <= 500000) {
    $Table_Number = $content['data']['max_table'];
   } else if($end_num > 500000) {
    $Calc         = intval($end_num/500000);
    $Table_Number = $content['data']['max_table']-$Calc;

   }

   $Array                     = array();
   $Array['Table_Number']     = $Table_Number;
   $Array['Max_ID']           = ($Table_Number*500000)-$end_num;
   $Array['Min_ID']           = ($Array['Max_ID']-$content['data']['limit_page'])-$start_num;

   return $Array;
  }

This function gives me the right Table_Number, but Max_ID and Min_ID are wrong.

Page limit is 100, if my page number 1 = $start_num is 1 and $end_num is 100 and Table_Number is 6 here Max_ID needs to be 3000000 and Min_ID need to be 2999900

if page number is 5000 = $start_num is 499901 and $end_num is 500000 and Table_Number is 6 here Max_ID needs to be 2500101 and Min_ID need to be 2500001

if page number is 5001 = $start_num is 500001 and $end_num is 500100 and Table_Number is 5 here Max_ID needs to be 2500000 and Min_ID need to be 2499900

...

I want to show via Order id Desc

Table 6:
Max id = 3000000
Min id = 2500001

Table 5:
Max id = 2500000
Min id = 2000001

How can I get the right Max_ID and Min_ID from this function so I can select the right way?

Answer 1

Try this:

$Array['Min_ID'] = 6 * 500000 - $end_num + 1;    
$Array['Max_ID'] = $Array['Min_ID'] + 99;

Answer 2

I successfully fixed the function:

  function Tables( $start_num, $end_num ) {
   global $content;

   if($end_num <= 500000) {
    $Table_Number = $content['data']['max_table'];
   } else if($end_num > 500000) {
    $Calc         = intval($end_num/500000);
    $Table_Number = $content['data']['max_table']-$Calc;
   }

   $Table_Extra                = $content['data']['max_table']-$Table_Number;

   if($Table_Extra == 0) {
    $Max_Table_ID              = $Table_Number*500000;
    $Min_ID                    = ($Max_Table_ID-$end_num)+1;
    $Max_ID                    = $Min_ID+99;
   } else if($Table_Extra > 0) {
    $Add_Extra                 = $Table_Extra*500000;
    $Max_Table_ID              = $Table_Number*500000;
    $Min_ID                    = (($Max_Table_ID-$end_num)+1)+$Add_Extra;
    $Max_ID                    = ($Min_ID+99)+$Add_Extra;
   }  

   $Array                     = array();
   $Array['Table_Number']     = $Table_Number;
   $Array['Max_ID']           = $Max_ID;
   $Array['Min_ID']           = $Min_ID;


   return $Array;
  }