SQL server查询某数据库下所有数据表信息

```sql
SELECT 
(case when a.colorder=1 then d.name else '' end) 表名,
a.colorder 字段序号,
a.name 字段名,
(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) 标识,
(case when (SELECT count(*) 
FROM sysobjects 
WHERE (name in (SELECT name
FROM sysindexes
WHERE (id = a.id) AND (indid in (SELECT indid
FROM sysindexkeys
WHERE (id = a.id) AND (colid in (SELECT colid
FROM syscolumns
WHERE (id = a.id) AND (name = a.name))))))) AND (xtype = 'PK')) > 0 then '√' else '' end) 主键,
b.name 类型,
a.length 占用字节数,
COLUMNPROPERTY(a.id,a.name,'PRECISION') as 长度,
isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as 小数位数,
(case when a.isnullable=1 then '√'else '' end) 允许空,
isnull(e.text,'') 默认值,
isnull(g.[value],'') AS 字段说明    
FROM  syscolumns a 
left join systypes b on a.xtype=b.xusertype
inner join sysobjects d on a.id=d.id  and  d.xtype='U' and d.name<>'dtproperties'
left join syscomments e on a.cdefault=e.id
left join sys.extended_properties g on a.id=g.major_id AND a.colid = g.minor_id  
order by a.id,a.colorder