知方可补不足~写了一个计算数据表占用存储空间的方法

DECLARE @tableName VARCHAR(50)
DECLARE @totalRecord BIGINT

SET @tableName = 'user_info'
SET @totalRecord = 1000000

SELECT  @tableName + '表中有' + LTRIM(STR(@totalRecord)) + '条数据时，占用的空间为:'
        + LTRIM(STR(SUM(c.length) * @totalRecord / 1024.0 / 1024.0)) + 'MB'
FROM    SYSTYPES T ,
        SYSCOLUMNS C
WHERE   T.XTYPE = C.XTYPE
        AND C.ID = ( SELECT ID
                     FROM   SYSOBJECTS
                     WHERE  NAME = @tableName
                   )
 
SELECT  TT.NAME ,
        DATA = @TOTALRECORD ,
        SIZE = ( SELECT STR(SUM(C.LENGTH) * @TOTALRECORD / 1024.0 / 1024.0)
                        + 'MB'
                 FROM   SYSTYPES T ,
                        SYSCOLUMNS C
                 WHERE  T.XTYPE = C.XTYPE
                        AND C.ID = TT.OBJECT_ID
               )
FROM    SYS.TABLES AS TT
ORDER BY TT.NAME