[单选题]若需统计“选课”表中已经选修了课程的学生人数,下面语句正确的是( )。A.SELECT COUNT(DISTINCT学生号)FROM选课B.SELECT COUNT(学生号)FROM选课C.SELECT COUNT(*)FROM选课D.SELECT COUNT(DISTINCT*)FROM选课
[单选题](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.snoB.) FROM sname,cno,grade FROM student,course WHERE student.sno =course.cnoC.) SELECT sname ,canme,grade FROM student,course,sc WHERE stud
[单选题]“查询选修了3门以上课程的学生的学生号”,正确的SQL语句是A.sELEcT S#FROM SC GROUP BY S#WHERE COUNT(*)>3B.SELECT s#FROM SC GROUP.BY S#HAVING COtJNT(*)>3C.sELECT S#FROM SC ORDER BY S#HAVING COUNT(*)>3D.sELECT S#FROM SC ORDER BY S#WHERE COUNT(*)>3
[试题]使用SQL语句求选修了法律课程的所有学生的学分总和SELECT ___ (学业分);FROM 学生;WHERE 科目号 IN;(SELECT 科目号FROM ___;WHERE 科目号=“法律”)
[试题]使用SQL语句求选修了法律课程的所有学生的学分总和SELECT______(学业分);PReM学生;WHERE 科目号 IN;(SELECT 科目号;F.ROH______;WHERE 科目号=“法律”)
[单选题]若要求“查询选修了3门以上课程的学生的学生号”,正确的SQL语句是( )。A.SELECT S# FROM SC GROUP BY S# WHERE COUNT(*)>3B.SELECT S# FROM SC GROUP BY S# HAVING COUNT(*)>3C.SELECT S# FROM SC ORDER BY S# WHERE COUNT(*)>3D.SELECT S# FROM SC ORDER BY S# HAVING COUNT(*)>3
[单选题]若要求“查询选修了3门以上课程的学生的学生号”,正确的SQL语句是A.SELECT S# FROM SC GROUP BY S# WHERE COUNT(*)> 3B.SELECT S# FROM SC GROUP BY S# HAVING COUNT(*)> 3C.SELECT S# FROM SC ORDER BY S# WHERE COUNT(*)> 3D.SELECT S# FROM SC ORDER BY S# HAVING COUNT(*)> 3
[单选题]查询选修了课程号为“C1”的学生的姓名和年龄,若用下列SQL的SELECT语句表达 时,错误的是( )。A.SELECT SNAME,AGE FROM S WHERE S .S#=(SELECT SC.S# FROM SC WHERE C.C#=’C 1’) B.SELECT SNAME,AGE FROM S,SC WHERE S.S#=SC.S# AND SC.C#=’C 1’ C.SELECT SNAME,AGE FROM S,SC WHERE S.S#=SC.S# AND SC.C#=’C
[单选题]查询选修了课程号为“C2”的学生号和姓名,若用下列SQL的SELECT语句表达时,哪一个是错误的?A.SELECT S.S#,SNAME FROM S WHERE S.S# (SELECT SC. S# FROM SC WHERE C#='C2')B.SELECT S.S#,SNAME FROMS,SC WHERE S.S#=SC.S# AND C#='C2'C.SELECT S.S#,SNAME FROM S,SC WHERE S.S=SC.S# AND C#='C2'ORDER
[单选题]查询选修了课程号为“C2”的学生号和姓名,若用下列SQL的SELECT语句表达是,( )是错误的。 A.SELECT S.S#,SNAME FROM S WHERE S.S# =(SELECT SC.S#FROM SC WHERE C#='C2') B.SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#='C2' C.SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#='C2'ORDER BY