final public static function isNullable($fieldName) {
		
		$db = Database::getInstance();
		$column = $db->describeColumn(static::TABLE_NAME, $fieldName);
		
		if (is_null($column)) {
			return NULL;
		}
		
		return ('YES'==$column->Null ? TRUE : FALSE);
		
	}
final public static function isNullable($fieldName) {
		
		$db = Database::getInstance();
		$column = $db->describeColumn(static::TABLE_NAME, $fieldName);
		
		if (is_null($column)) {
			return NULL;
		}
		
		return ('YES'==$column->Null ? TRUE : FALSE);
		
	}
final public static function isNullable ( $ fieldName ) { $ db = Database :: getInstance ( ) ; $ column = $ db -> describeColumn ( static :: TABLE_NAME , $ fieldName ) ; if ( is_null ( $ column ) ) { return NULL ; } return ( 'YES' == $ column -> Null ? TRUE : FALSE ) ; }
Check whether the DB-table-field is capable to store null values.

@param	string	DB-table-field name.

@return	bool|NULL
Check whether the DB - table - field is capable to store null values .