code: public static function countBy($strColumn=null, $varValue=null, array $arrOptions=array())
  	{
  		if (static::$strTable == '')
  		{
  			return 0;
  		}
  
  		$arrOptions = array_merge
  		(
  			array
  			(
  				'table'  => static::$strTable,
  				'column' => $strColumn,
  				'value'  => $varValue
  			),
  
  			$arrOptions
  		);
  
  		$strQuery = static::buildCountQuery($arrOptions);
  
  		return (int) Database::getInstance()->prepare($strQuery)->execute($arrOptions['value'])->count;
  	}
docs: Return the number of records matching certain criteria
  
  @param mixed $strColumn  An optional property name
  @param mixed $varValue   An optional property value
  @param array $arrOptions An optional options array
  
  @return integer The number of matching rows