Question

我有一个日志表，以字节为单位存储各种文件大小。我希望能够查询数据库并返回已经转换为MB GB等的最小浮点数。目前我可以返回以MB为单位的值但是如何继续进一步划分为最小值并附加单位？ / p>

SELECT CONCAT( ROUND( SUM( data_transferred ) /1048576, 2 ) ,  ' MB' ) 
FROM  `logs`

任何帮助都将不胜感激。

更新：

基于链接voodoo417，我将查询更新为以下内容，将最相关的文件大小输出到两个小数位并附加单位（1000字节，1 KB，500 MB，2 GB等）：< / p>

SET @bytes := (SELECT SUM(data_transferred) FROM wp_ddownload_statistics);

SELECT
    CASE
WHEN ABS(@bytes) < 1024 THEN CONCAT( ROUND( @bytes, 2 ), ' Bytes')
      WHEN ABS(@bytes) < 1048576 THEN CONCAT( ROUND( (@bytes/1024), 2 ), ' KB')
      WHEN ABS(@bytes) < 1073741824 THEN CONCAT( ROUND( (@bytes/1048576), 2 ), ' MB')
      WHEN ABS(@bytes) < 1099511627776 THEN CONCAT( ROUND( (@bytes/1073741824), 2 ), ' GB' )
      WHEN ABS(@bytes) < 1125899906842624 THEN CONCAT( ROUND( (@bytes/1099511627776), 2 ), ' TB')
      WHEN ABS(@bytes) < 1152921504606846976 THEN CONCAT( ROUND( (@bytes/1125899906842624), 2 ), ' PB' )
      WHEN ABS(@bytes) < 1180591620717411303424 THEN CONCAT( ROUND( (@bytes/1152921504606846976) ,2), ' EB' )
      WHEN ABS(@bytes) < 1208925819614629174706176 THEN CONCAT( ROUND( (@bytes/1180591620717411303424), 2), ' ZB' )
      WHEN ABS(@bytes) < 1237940039285380274899124224 THEN CONCAT( ROUND( (@bytes/1208925819614629174706176), 2), ' YB' )
      WHEN ABS(@bytes) < 1267650600228229401496703205376 THEN CONCAT( ROUND( (@bytes/1237940039285380274899124224), 2), ' BB' )
    END

Answer 1

我知道这是一个老问题，但我最近也在寻找相同的东西，并且发现MySQL 5.7为此目的添加了format_bytes功能：

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

Answer 2

我有一个更优雅的解决方案（也使用用户定义的功能）：

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

更新

更好，可以在外部程序中使用：

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

当filesize为0时，Renaat的代码失败（显然你不能从零开始做LOG）。因此@log填充为null，CONCAT也生成null。正确的解决方法是：

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 4

尽管在 2016 年得到了回答，但遗憾的是，MariaDB 中仍未找到有关使用 format_bytes 的最佳答案。

我修改了 here 中的查询以创建一个我可以使用的函数。

FUNCTION `format_bytes`(val float) RETURNS varchar(20) CHARSET latin1
BEGIN
    DECLARE pw smallint;
    IF val < 1024 THEN
        return CONCAT(val, ' B');
    END IF;
    SET pw = LEAST(7, FLOOR(LOG(val) / LOG(1024)));
    RETURN CONCAT(ROUND(val / POW(1024, pw), 2), ' ', SUBSTR('KMGTPEZY', pw, 1), 'B');
END



>>> SELECT format_bytes(512), format_bytes(18446644073709551615);
+-------------------+------------------------------------+
| format_bytes(512) | format_bytes(18446644073709551615) |
+-------------------+------------------------------------+
| 512 B             | 16.00 EB                           |
+-------------------+------------------------------------+

可以调整一些东西以更接近地模仿 MySQL format_bytes，但这不是我的目标。

Answer 5

SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[5]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[6]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[7]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[8]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[11]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[12]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[14]/div[2]/a') as t(v) union ALL SELECT t.v.value('.','nvarchar(max)') as [Name Of Brand], --t.v.value('@title','nvarchar(max)') as [Title Of Brand], t.v.value('@href','nvarchar(max)') as [URL Local], t.v.value('@tppabs','nvarchar(max)') as [URL Site] FROM @htmlXML.nodes('div/div[15]/div[2]/a') as t(v)

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

MySQL将字节转换为千字节，兆字节，千兆字节

5 个答案:

更新