select * from INFORMATION_SCHEMA.TABLES

SELECT   
 (case when a.colorder=1 then d.name else ‘‘ end) as 表名,--如果表名相同就返回空  
     a.colorder as 字段序号,  
     a.name as 字段名,  
     (case when COLUMNPROPERTY( a.id,a.name,‘IsIdentity‘)=1 then ‘√‘else ‘‘ end) as 标识,  
     (case when (SELECT count(*) FROM sysobjects--查询主键  
                     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) as 主键,--查询主键END  
 b.name as 类型,  
 a.length as 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) as 允许空,  
 isnull(e.text,‘‘) as 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