查询student表中的所有非空email信息，以下语句正确的是（）。A、Select email from student where email !=nullB、Select email from student where email not is nullC、Select email from student where email nullD、Select email from student where email is not null

对于学生信息表：student(sno，sname，sex，age，dept)，能够得到年龄在20岁到22岁之间的学生的姓名和学号的语句是

A．SELECT * FROM student WHERE age BETWEEN 20 AND 22

B．SELECT sname，sno FROM student WHERE age BETWEEN 20 AND 22

C．SELECT sname，sno FROM student WHERE age＞=20

D．SELECT sname，sno FROM student WHERE age＜=22

根据SQL标准，下面哪条语句与select min(age) from student等效?()

A select age from student where age >= min(age)

B select distinct age from student where age >= all min(age)

C select distinct a.age from student a where a.age<= any (select distinctb.age from student b)

D select distinct a.age from student a where a.age<= all (select distinct b.age from student b)

（40）查找学生姓名及其所选修课程号和成绩，正确的 SQL 语句是

A）SELECT sname FROM student, SELECT cno,grade FROM sc WHERE student.sno =sc.sno

B） FROM sname,cno,grade FROM student,course WHERE student.sno =course.cno

C） SELECT sname ,canme,grade FROM student,course,sc WHERE student.sno =sc.sno and sc.c

no=course.cno

D） SELECT sname ,cno,grade FROM student,sc WHERE student.sno =sc.sno

使用SQL语句从表STUDENT中查询所有姓王的同学的信息，正确的命令是：______。

A．SELECT*FROM STUDENT WHERE LEFT(姓名，2)=“王”

B．SELECT*FROM STUDENT WHERE RIGHT(姓名，2)=“王”

C．SELECT*FROM STUDENT WHERE TRIM(姓名，2)=“王”

D．SELECT*FROM STUDENT WHERE STR(姓名，2)=“王”

查找学生姓名及其所选修课程的课程号和成绩,正确的SQL语句是

A．SELECT sname FROM student,SELECT cno,grade FROM sc WHERE student.sno=sc.sno

B．SELECT sname,cno,grade FROM student,course WHERE student.sno=course.cno

C．SELECT sname,cname,grade FROM student,course,sc WHERE student.sno=sc.sno and sc.cno=course,cno

D．SELECT sname,cno,grade FROM student,sc WHERE student.sno=sc.sno

根据SQL标准，下面哪句语句能够找出年龄最小的同学?其中age为学生表student中的年龄字段，sno为学生的学号。()

A select max(age) from student

B select sno from student where age = max(age)

C select sno from student having age = max(age)

D select sno from student a where a.age<= (select min(b.age) from student b)

根据SQL标准，要查询表student中所有年龄age小于所有学生的平均年龄的记录，下面哪条语句适用?()

A select * from student where age< avg(age)

B select * from student having age< avg(age)

C select * from student a where a.age< (select avg(b.age) from student b)

D select * from student a where (select avg(b.age) from student b ) >= a.age

使用SQL语句从表STUDENT中查询所有姓王的同学的信息，正确的命令是：A）SELECT*FROM STUDENT WHERE LEFT（姓名，2）＝“王”B）SELECT*FROM STUDENT WHERE RIGHT（姓名，2）＝“王”C）SELECT*FROM STUDENT WHERE TRIM（姓名，2）＝“王”D）SELECT*FROM STUDENT WHERE STR(姓名，2)=“王”

对于数据表：student(sno,sname,sex,age,grade)，查询学习成绩为空的学生的学号和姓名，下面语句正确的是______。

A．SELECT sno,sname FROM student WHERE gade=NULL

B．SELECT sno,sname FROM student WHERE grade IS NULL

C．SELECT sno,age FROM student WHERE grade IS NULL

D．SELECT mo,age FROM student WHERE grade=NULL

对于学生信息表：student(sno，sname，sex，age，dept)，要查询所有刘姓学生的信息，正确的语句是

A．SELECT * FROM student WHERE sname LIKE'刘 * '

B．SELECT * FROM student WHERE sname LIKE'刘 $'

C．SELECT * FROM student WHERE sname LIKE'刘%'

D．SELECT * FROM student WHERE sname LIKE'刘&'