【单选题】SQL数据定义语言中,表示外码约束的关键字是( )
【简答题】Students are being forced to take additional exams to get into leading universities because good A-levels do not always indicate the brightest candidates. Sixth-formers applying to courses such as med...
【单选题】某孔的最大极限尺寸为φ60.220mm,最小极限尺寸为φ60. 100mm则该孔的尺寸公差为() 。
【判断题】罐头厂制作罐头而买的苹果和居民购买的苹果都应计入国内生产值。
【单选题】From paragraph two, we can infer that ______.
A.
Bush forced the National Renewable Energy Laboratory to lay off workers
B.
Bush visited the lab (NREL before the laid-off of 32 workers
C.
the 32 workers might be reemployed after Bush' s visit
D.
Bush carried $ 5 million cash to the NREL when he visited there
【判断题】罐头厂制作罐头而买的苹果和居民购买的苹果都应计人国内生产值。
【单选题】SQL数据定义语句中,表示外键约束的关键字是( )
【判断题】罐头厂制作罐头而买的苹果和居民购买的苹果都应计入国内生产总值。
【判断题】T-SQL 数据定义语言中,表示外键约束的关键字是FOREIGN KEY。
【单选题】SQL数据定义语言中,表示外键约束的关键字是()。