5сем / files / sales

DROP FUNCTION IF EXISTS sales;
DELIMITER //
CREATE FUNCTION sales(summa int)
returns VARCHAR(150) DETERMINISTIC
begin
	SET @message = 'Процент успешных продаж ';
    SET @cikl = (SELECT MAX(id_appeal) FROM my_library.appeals);
    SET @count = 0;
    WHILE @cikl > 0 DO
		SET @total = (SELECT (total) from my_library.appeals where id_appeal = @cikl);
        CASE
			WHEN @total > summa THEN set @count = @count + 1;
            else begin end;
		END case;
		set @cikl = @cikl -1;
	END WHILE;
    set @procent = ROUND(@count/(SELECT MAX(id_appeal) FROM my_library.appeals)*100);
    SET @message = (select concat(@message , @procent, '%'));
	return @message;
end; // select sales(150);