-- 查看所有的数据库
select name from sys.databases order by name;-- 查看所有的表
use [你的数据库名];
-- select * from sys.objects order by type;
-- select * from sys.objects where type = 'u';
-- select object_id,name from sys.objects where type = 'u';
select name 表名 from sys.objects where type = 'u';-- 查看表描述
SELECT t.name 表名,prop.value 描述   
FROM sys.tables t  
LEFT JOIN sys.extended_properties prop 
ON prop.major_id=t.object_id AND prop.minor_id = 0 and prop.class = 1
ORDER BY t.name;-- 查看表的信息
use [你的数据库名];
select
col. name  as  ColumnName,
col.max_length  as  DataLength,
col.is_nullable  as  IsNullable,
t. name  as  DataType,
ep.value  as  Description,
(select  top  1 ind.is_primary_key  from  sys.index_columns icleft  join  sys.indexes indon  ic.object_id=ind.object_idand  ic.index_id=ind.index_idand  ind. name  like  'PK_%'where  ic.object_id=obj.object_idand  ic.column_id=col.column_id
)  as  IsPrimaryKey
from  sys.objects obj
inner  join  sys.columns col
on  obj.object_id=col.object_id
left  join  sys.types t
on  t.user_type_id=col.user_type_id
left  join  sys.extended_properties ep
on  ep.major_id=obj.object_id
and  ep.minor_id=col.column_id
and  ep. name = 'MS_Description'
where  obj. name ='[你的表名]';

参考这里：SqlServer 之快速查看表结构 (表描述及字段说明).
查看SQL Server的表字段类型、长度、描述以及是否可为null.