Question

这是获取物理驱动器的空闲和总磁盘空间的代码，数据存储在临时数据库#output中。我想要做的就是我想比较freespace表中#output列中的每个值与“1024000”，如果值小于此值，那么我想将值放在另一个值中表

我是SQL的新手，所以我不知道该怎么做。

P.S。驱动器的数量可能会有所不同，因此我需要一个通用的解决方案。

declare @svrName varchar(255)
declare @sql varchar(400)

set @svrName = @@SERVERNAME
set @sql = 'powershell.exe -c "Get-WmiObject -ComputerName ' + QUOTENAME(@svrName,'''') + ' -Class Win32_Volume -Filter ''DriveType = 3'' | select name,capacity,freespace | foreach{$_.name+''|''+$_.capacity/1048576+''%''+$_.freespace/1048576+''*''}"'
--creating a temporary table
CREATE TABLE #output
(line varchar(255))
--inserting disk name, total space and free space value in to temporary table

insert #output
EXEC xp_cmdshell @sql

select rtrim(ltrim(SUBSTRING(line,1,CHARINDEX('|',line) -1))) as drivename
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('|',line)+1,
      (CHARINDEX('%',line) -1)-CHARINDEX('|',line)) )) as Float)/1024,0) as 'capacity(GB)'
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('%',line)+1,
      (CHARINDEX('*',line) -1)-CHARINDEX('%',line)) )) as Float) /1024 ,0)as 'freespace(GB)'
from #output
where line like '[A-Z][:]%'
order by drivename

Answer 1

declare @svrName varchar(255)
declare @sql varchar(400)

set @svrName = @@SERVERNAME
set @sql = 'powershell.exe -c "Get-WmiObject -ComputerName ' + QUOTENAME(@svrName,'''') + ' -Class Win32_Volume -Filter ''DriveType = 3'' | select name,capacity,freespace | foreach{$_.name+''|''+$_.capacity/1048576+''%''+$_.freespace/1048576+''*''}"'
--creating a temporary table
CREATE TABLE #output
(line varchar(255))
--inserting disk name, total space and free space value in to temporary table

insert #output
EXEC xp_cmdshell @sql

select rtrim(ltrim(SUBSTRING(line,1,CHARINDEX('|',line) -1))) as drivename
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('|',line)+1,
      (CHARINDEX('%',line) -1)-CHARINDEX('|',line)) )) as Float)/1024,0) as 'capacity(GB)'
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('%',line)+1,
      (CHARINDEX('*',line) -1)-CHARINDEX('%',line)) )) as Float) /1024 ,0)as 'freespace(GB)'
from #output
where line like '[A-Z][:]%'
having (CHARINDEX('*',line) -1)-CHARINDEX('%',line)) )) as Float) /1024 ,0) < 20
order by drivename

在评论中直接回答您的问题。

使用函数或计算字段时，不能将它们放在WHERE子句上，因此必须使用HAVING。在此解决方案中，我使用了 freespace（GB）的计算字段，将其放在HAVING子句和选定值＆gt;不到20岁。

告诉我们它是否有效，因为我不知道你是否可以在这些类型的函数中使用HAVING。如果下面的其他解决方案不起作用：

declare @svrName varchar(255)
declare @sql varchar(400)

set @svrName = @@SERVERNAME
set @sql = 'powershell.exe -c "Get-WmiObject -ComputerName ' + QUOTENAME(@svrName,'''') + ' -Class Win32_Volume -Filter ''DriveType = 3'' | select name,capacity,freespace | foreach{$_.name+''|''+$_.capacity/1048576+''%''+$_.freespace/1048576+''*''}"'
--creating a temporary table
CREATE TABLE #output
(line varchar(255))
--inserting disk name, total space and free space value in to temporary table

insert #output
EXEC xp_cmdshell @sql

select rtrim(ltrim(SUBSTRING(line,1,CHARINDEX('|',line) -1))) as drivename
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('|',line)+1,
      (CHARINDEX('%',line) -1)-CHARINDEX('|',line)) )) as Float)/1024,0) as 'capacity(GB)'
      ,round(cast(rtrim(ltrim(SUBSTRING(line,CHARINDEX('%',line)+1,
      (CHARINDEX('*',line) -1)-CHARINDEX('%',line)) )) as Float) /1024 ,0)as 'freespace(GB)'
into #output_2
from #output
where line like '[A-Z][:]%'
order by drivename

select *
from #output_2
where [freespace(GB)] < 20

在这种情况下，您将#output中的值插入另一个表（＃output_2）中，以便您可以直接使用WHERE子句。

如何在sql表中移动和比较列值？

1 个答案: