SQL Server 系统表使用－查询指定数据库中用户表及其列、数据类、长度

select t1.id,t1.name,t2.name,t2.xtype,
case when t2.xtype=56 or t2.xtype=61 then t3.name
else t3.name+'('+convert(varchar,t2.length)+')' end,
case when t2.isnullable=1 then ''
else 'Y' end
from sysobjects t1,syscolumns t2,systypes t3
where t1.xtype='U'and t1.id=t2.id
and t2.xtype=t3.xtype
--and t1.name='CompanyInfo'
order by t1.id,t2.colid