MySQL Convert Bytes to Kilobytes, Megabytes, Gigabytes

Question

I have a logs table that stores various file sizes in bytes. I want to be able to query the database and return the smallest possible float which has been converted to MB GB

Answer 1

I know this is an old question, but I was looking for the same thing recently, and found out that MySQL 5.7 added format_bytes function exactly for this purpose:

mysql> SELECT format_bytes(512), format_bytes(18446644073709551615);
+-------------------+------------------------------------+
| format_bytes(512) | format_bytes(18446644073709551615) |
+-------------------+------------------------------------+
| 512 bytes         | 16383.91 PiB                       |
+-------------------+------------------------------------+

Answer 2

Renaat's code is failing when filesize is 0 (obviously you can't do LOG from zero). Therefore @log is filled with null and CONCAT produce null as well. Correct fix is:

SET @filesize = 536870912;
SET @log = IFNULL(TRUNCATE(LOG(1024, @filesize), 0),0);
SELECT CONCAT(ROUND(@filesize / POW(1024, @log), 2), ' ',
            ELT(@log + 1, 'Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB', 'BB'));

Answer 3

select concat(round(data*1048576/1073741824,2),' GB')

for example: 1024 = 1gb select concat(round(1024*1048576/1073741824,2),' GB') 1gb

Answer 4

I have a more elegant solution (also using a user defined function):

CREATE FUNCTION `format_filesize`(filesize FLOAT) RETURNS varchar(20) CHARSET utf8
BEGIN

DECLARE n INT DEFAULT 1;

LOOP
    IF filesize < 1024 THEN
        RETURN concat(round(filesize, 2), ' ', elt(n, 'Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB', 'BB'));
    END IF;
    SET filesize = filesize / 1024;
    SET n = n + 1;
END LOOP;

END

UPDATE:

Even better, and can be used outside procedures:

SET @filesize = 536870912;
SET @log = IFNULL(TRUNCATE(LOG(1024, @filesize), 0),0);
SELECT CONCAT(ROUND(@filesize / POW(1024, @log), 2), ' ',
            ELT(@log + 1, 'Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB', 'BB'));