SQL语言中的ROLLBACK语句的主要作用是______。
A.终止程序
B.保存数据
C.事务提交
D.事务回滚
参考答案:D
Find out the mistakes and correct them. 找出错误并改正。
( ) 1. Did you remember play games yesterday ?
A B C
( ) 2. Many peoples are in the store.
( ) 3. How are you make cookies ?
( ) 4. I call Li Ming in the phone.
( ) 5. Here the bus coming.
小红计划到外婆家度暑假,为此她准备了一件粉色衬衣,一件白色衬衣,又买了三条不同款式的裙子:一步裙、太阳裙和牛仔裙.
(1)她一共有多少种搭配方法?
(2)如果在30天中她每天都变换一种搭配,她有几天穿白衬衣?几天穿牛仔裙?有几天白衬衣配牛仔裙?