11.4. 通过SQL语句来更改用户的密码 
修改别人的,需要sysadmin role 
EXEC sp_password NULL, 'newpassword', 'User' 
如果帐号为SA执行EXEC sp_password NULL, 'newpassword', sa 
11.5. 怎么判断出一个表的哪些字段不允许为空? 
select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS where IS_NULLABLE='NO' and TABLE_NAME=tablename 
11.6. 如何在数据库里找到含有相同字段的表? 
a. 查已知列名的情况 
SELECT b.name as TableName,a.name as columnname 
From syscolumns a INNER JOIN sysobjects b 
ON a.id=b.id 
AND b.type='U' 
AND a.name='你的字段名字' 
b. 未知列名查所有在不同表出现过的列名 
Select o.name As tablename,s1.name As columnname 
From syscolumns s1, sysobjects o 
Where s1.id = o.id 
And o.type = 'U' 
And Exists ( 
Select 1 From syscolumns s2 
Where s1.name = s2.name 
And s1.id <> s2.id 
) 
11.7. 查询第xxx行数据 
假设id是主键: 
select * 
from (select top xxx * from yourtable) aa 
where not exists(select 1 from (select top xxx-1 * from yourtable) bb where aa.id=bb.id) 
如果使用游标也是可以的 
fetch absolute [number] from [cursor_name]