题目7单选题
对于校园卡的表SCHOOLCARD (S_NO,ID,SUM_MONEY)给学号为"2000001"的学生饭卡充值100块钱,正确的SQL语句是( )A. update SCHOOLCARD set SUM_MONEY=100 where S_NO='2000001'B. update SCHOOLCARD set SUM_MONEY=SUM_MONEY +100 where S_NO='2000001'C. update SCHOOLCARD set SUM_MONEY=100D. update SCHOOLCARD set SUM_MONEY=SUM_MONEY +100