code: public static function convertOrderField($table, $field)
  	{
  		$objDatabase = Database::getInstance();
  
  		// Get the non-empty rows
  		$objRow = $objDatabase->query("SELECT id, $field FROM $table WHERE $field LIKE '%,%'");
  
  		// Convert the comma separated lists into serialized arrays
  		while ($objRow->next())
  		{
  			$objDatabase->prepare("UPDATE $table SET $field=? WHERE id=?")
  						->execute(serialize(explode(',', $objRow->$field)), $objRow->id);
  		}
  
  		static::convertMultiField($table, $field);
  	}
docs: Convert an order source field to UUIDs
  
  @param string $table The table name
  @param string $field The field name