SQL中如何查询各个数据表的大小

declare @id            int
declare @type          character(2)                
declare @pages         int                       
declare @dbname        sysname
declare @dbsize        dec(15,0)
declare @bytesperpage dec(15,0)
declare @pagesperMB    dec(15,0)

create table #spt_space
(
    [objid]         int null,
    [rows]          int null,
    [reserved]      dec(15) null,
    [data]          dec(15) null,
    [indexp]        dec(15) null,
    [unused]        dec(15) null
)

set nocount on

-- Create a cursor to loop through the user   tables

declare c_tables cursor for
select id from sysobjects where xtype = 'U'

open c_tables fetch next from c_tables into @id

while @@fetch_status = 0
begin
    /* Code from sp_spaceused */
    insert into #spt_space (objid, reserved)
    select objid = @id, sum(reserved)
    from sysindexes
    where indid in (0, 1, 255)   and   id = @id
   
   
    select @pages = sum(dpages)
    from sysindexes
    where indid < 2
    and   id = @id
   
    select @pages = @pages + isnull(sum(used), 0)
    from sysindexes
    where indid = 255    and   id = @id
   
    update #spt_space   set data = @pages
    where objid = @id
   
    /* index: sum(used) where indid in (0, 1, 255) - data */
   
    update #spt_space
    set indexp = (select sum(used)
    from sysindexes
    where indid in (0, 1, 255)
    and id = @id) - data
    where objid = @id
   
    /* unused: sum(reserved) - sum(used) where indid in (0, 1, 255) */
    update #spt_space
    set unused = reserved - (
                                select sum(used)
                                from sysindexes
                                where indid in (0, 1, 255) and id = @id
                            )
    where objid = @id
   
    update #spt_space   set [rows] = i.[rows]
    from sysindexes i
    where i.indid < 2   and i.id = @id    and objid = @id
   
    fetch next from c_tables   into @id

end

select TableName = (select left(name,60) from sysobjects where id = objid),
        [Rows] = convert(char(11), rows),
        ReservedKB = ltrim(str(reserved * d.low / 1024.,15,0) + ' ' + 'KB'),
        DataKB = ltrim(str(data * d.low / 1024.,15,0) + ' ' + 'KB'),
        IndexSizeKB = ltrim(str(indexp * d.low / 1024.,15,0) + ' ' + 'KB'),
        UnusedKB = ltrim(str(unused * d.low / 1024.,15,0) + ' ' + 'KB')
from         #spt_space, master.dbo.spt_values d
where         d.number = 1
and         d.type = 'E'
order by reserved desc

drop table #spt_space
close c_tables
deallocate c_tables