【单选题】下列哪一种辅因子的生成可通过测定340nm处吸光度的降低数来表示:
【简答题】This is my school. There are many trees and flowers in it. It’s very beautiful. The teaching building is big and tall. There is a big playground in our school. After 4:30 in the afternoon, many studen...
【单选题】已知SN是一个字符类型的字段,有查询语句:SELECT SN FROM S WHERE SN LIKE ’AB%’ 该查询语句的执行结果是()。
【单选题】已知SN是字符型字段,下列SQL查询语句: SELECT SN FROM S WHERE SN LIKE 'AB%' 的执行结果是为()
B.
找出仅含有3个字符且前两个字符为AB的所有SN字段
【单选题】查询语句中,错误的是( )。
A.
SELECT Sno, COUNT(*) FROM SC GROUP BY Sno
B.
SELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*) > 3
C.
SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*) > 3
D.
SELECT Sno FROM SC GROUP BY Sno
【简答题】I can’t find Dr.Green anywhere in the office buildin9.Where__________he have gone?
【单选题】已知SN是一个字符类型的字段,有查询语句:SELECT SN FROM S WHERE SN LIKE 'AB%' 该查询语句的执行结果是
【单选题】SQL语言中使用BETWEEN语句查询年龄在30~38岁之间员工号的语句 SELECT E# FROM S WHERE EA BETWEEN 30 AND 38 中( )。
【单选题】假设有如下两个关系R和S: 则以下查询语句:SELECT A,B,C,D,E FROM R,S WHERE R.A=S.A实现的是R和 S的什么运算?
【单选题】已知SN是一个字符型字段,下列SQL查询语句( ) 。 SELECT SN FROM S WHERE SN LIKE ‘AB%’;的执行结果为
B.
找出仅含 3 个字符且前两个字符为‘AB’的 SN 字段
D.
找出含有 3 个字符‘AB%’的所有 SN 字段