查询数据库所有数据库名，表名，所有字段

所有数据库名

Select Name From Master..SysDatabases order By Name

查询当前数据库名

SELECT DB_NAME()

表名

USE '数据库名'
Select Name From SysObjects Where XType='U' order By Name  

所有字段

Select name From SysColumns Where id=Object_Id('Order')

SELECT a.[name] as '字段名',a.length '长度',c.[name] '类型',e.value as '字段说明' 
 FROM syscolumns  a 
left join  systypes  b on  a.xusertype=b.xusertype 
left join systypes c on  a.xtype = c.xusertype 
inner join sysobjects  d on  a.id=d.id and d.xtype='U' 
left join sys.extended_properties e on a.id = e.major_id and a.colid = e.minor_id and e.name='MS_Description'
where d.name='Order'