A.SELECT *FROM user WHERE username =’1’OR ’1’=’1’AND password =’’
B.SELECT *FROM user WHERE username =’1’OR ’1’=’1’#AND password =’’
C.SELECT *FROM user WHERE username =’1’OR ’1’=’1’AND password =’1’OR ’1’=’1’
D.SELECT *FROM user WHERE username =’1’AND password =’’OR ’1’=’1’
E.SELECT *FROM user WHERE username =’1’AND password =’1’#