1 SELECT     2 (case when a.colorder=1 then d.name else '' end) as 表名,--如果表名相同就返回空   syscolumns(表字段信息表) a  sysobjects d  3      a.colorder as 字段序号,    4      a.name as 字段名,    5      (case when COLUMNPROPERTY( a.id,a.name, 'IsIdentity' )=1 then '√' else '' end) as 标识,   --返回IsIdentity的值，IsIdentity只有两个值：0、1 6      (case when (SELECT count(*) FROM sysobjects--查询主键    7                      WHERE (name in     8                              (SELECT name FROM sysindexes     9                              WHERE (id = a.id)   AND (indid in    10                                      (SELECT indid FROM sysindexkeys   11                                        WHERE (id = a.id) AND (colid in    12                                          (SELECT colid FROM syscolumns   13                                          WHERE (id = a.id) AND (name = a.name))   14                          )))))    15          AND (xtype = 'PK' ))>0 then '√' else '' end) as 主键,--查询主键END   16 b.name as 类型,   --systypes b 17 a.length as 占用字节数,   18 COLUMNPROPERTY(a.id,a.name,'PRECISION' ) as    长度,   19 isnull(COLUMNPROPERTY(a.id,a.name,'Scale' ),0) as 小数位数,   20 (case when a.isnullable=1 then '√' else '' end) as 允许空,   21 isnull(e.text,'' ) as 默认值,   --syscomments e 22 isnull(g.[value],'' ) AS 字段说明    --sys.extended_properties g (字段信息表)23 FROM syscolumns a left join systypes b    24 on a.xtype=b.xusertype   25 inner join sysobjects d    26 on a.id=d.id and d.xtype='U' and d.name<> 'dtproperties'    27 left join syscomments e   28 on a.cdefault=e.id   29 left join sys.extended_properties g   30 on a.id=g.major_id AND a.colid = g.minor_id    31      where d.name='systempara' --所要查询的表   32 order by a.id,a.colorder

• select * from sys.extended_properties--字段信息表
• select * from syscolumns--表字段信息表
• select * from sysobjects where sysobjects.type='u'--数据库所有的用户创建的表的信息
• select * from sysobjects where sysobjects.type='s'--数据库所有的系统表的信息
• select * from syscomments --所有的触发器的东西
• --COLUMNPROPERTY 返回有关列或过程参数的信息