How to construct a MySQL while loop PHP multidimensional array for datagrid framework

I am not clear how to construct a multidimensional array to create a simple datagrid framework. I have a number of class methods with crud select statements from MySQL tables in the format:

<?php

  function table1()
  {
    $sql = "SELECT * FROM `table1`";
    $this->database_select($sql);
    $result = $this->getMySQLresult($sql);
    $html = "<table>";
    while ($row = mysql_fetch_array( $result ))
    {
      $html .= "<tr><td>".$row['field_a']."</td><td>".$row['field_b']."</td></tr>";
    }
    $html .= "</table>";
    return $html;
  }

  function table2()
  {
    $sql = "SELECT * FROM `table2`";
    $this->database_select($sql);
    $result = $this->getMySQLresult($sql);
    $html = "<table>";
    while ($row = mysql_fetch_array( $result ))
    {
      $html .= "<tr><td>".$row['field_x']."</td><td>".$row['field_y']."</td></tr>";
    }
    $html .= "</table>";
    return $html;
  }

?>

where the MySQL tables look like:

table1

+---------+--------------+------+-----+---------+----------------+
| Field   | Type         | Null | Key | Default | Extra          |
+---------+--------------+------+-----+---------+----------------+
| id      | bigint(12)   | NO   | PRI | NULL    | auto_increment |
| field_a | varchar(128) | NO   |     | NULL    |                |
| field_b | varchar(128) | NO   |     | NULL    |                |
+---------+--------------+------+-----+---------+----------------+

table 2

+---------+--------------+------+-----+---------+----------------+
| Field   | Type         | Null | Key | Default | Extra          |
+---------+--------------+------+-----+---------+----------------+
| id      | bigint(12)   | NO   | PRI | NULL    | auto_increment |
| field_x | varchar(128) | NO   |     | NULL    |                |
| field_y | varchar(128) | NO   |     | NULL    |                |
+---------+--------------+------+-----+---------+----------------+

I am trying to replace all these methods with a single datagrid method, selecting information about each individual table from two summary grid tables - one with properties of each table (table name and the select sql statement for that table) and the other with field names and headings for each individual table:

grid_properties

+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | bigint(12)   | NO   | PRI | NULL    | auto_increment |
| table      | varchar(128) | NO   |     | NULL    |                |
| select_sql | varchar(128) | NO   |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+

grid_fields

+--------------------+--------------+------+-----+---------+----------------+
| Field              | Type         | Null | Key | Default | Extra          |
+--------------------+--------------+------+-----+---------+----------------+
| id                 | bigint(12)   | NO   | PRI | NULL    | auto_increment |
| grid_properties_id | bigint(12)   | NO   |     | NULL    |                |
| heading            | varchar(128) | NO   |     | NULL    |                |
| field              | varchar(128) | NO   |     | NULL    |                |
+--------------------+--------------+------+-----+---------+----------------+

Data in the grid_fields.field column is intended to just be the field name of the table referenced in grid_properties.table, related through grid_properties.id::grid_fields.grid_properties_id.

The method I am using to construct the datagrid has a multidimensional array in the last while loop that has something wrong with it. What is the correct way to construct this?

<?php

  function grid_schema($table)
  {
    // Get information about $table from the grid_properties table
    $sql = "SELECT * FROM `grid_properties` WHERE `table` LIKE '".$table."'";
    $this->database_select ($sql);
    $result1 = mysql_query ($sql);
    $properties = mysql_fetch_array ($result1);
    $properties_sql = $properties['select_sql'];
    $id = $properties['id'];

    // Get information about the grid field names
    $fields_sql = "SELECT * FROM `grid_fields` WHERE `grid_properties_id` ='".$id."'";
    $this->database_select ($fields_sql);
    $fields_result = mysql_query ($fields_sql);

    // Display the Table Headings
    $html = "<table><tr>";
    while ($fields_row = mysql_fetch_array ( $fields_result ))
    { $html .= "<th>".$fields_row['heading']."</th>"; }
    $html .= "</tr>";

    // Perform the SQL query from the grid_properties table
    $this->database_select ($properties_sql);        
    $properties_result = mysql_query ($properties_sql);
    while ($properties_row = mysql_fetch_array ($properties_result))
    {
      // Print out the contents of each row
      $html .= "<tr>";
      while ($fields_row = mysql_fetch_array( $fields_result ))
      {
        // This is where I am having problems
        $html .= "<td>".$properties_row[$fields_row]['field']."</td>";
      }
    }
    $html .= "</table>";
    return $html;
  }
?>