若要求查找‘李’姓学生的学生号和姓名,正确的SQL语句是( )。 A: SELECT S#,SNAME FROM S WHERE SNAME=’李%’ B: SELECT S#,SNAME FROM S WHERE SNAME LIKE ’李%’ C: SELECT S#,SNAME FROM S WHERE SNAME=’%李%’ D: SELECT S#,SNAME FROM S WHERE SNAME LIKE ’%李%’

若要求查找姓名中第一个字为“刘”的学生号和姓名。下面列出的SQL语句中， ( )是正确的。 A: SELECT S#,SNAME FROM，S WHERE SNAME='刘%' B: SELECT S#,SNAME FROM S WHERE SNAME='刘_' C: SELECT S#,SNAME FROM S WHERES NAME LIKE'刘％' D: SELECT S#,SNAME FROM S WHERES NAME LIKE'刘'

有关系S(S#，SNAME，SAGE)，C(C#，CNAME)，SC(S#，C#，GRADE)。若要查找分数(grade)不及格的学生姓名(sname)，则以上正确的有？（ ） A: SELECT sname FROM s, sc WHERE grade<60 B: SELECT sname FROM s WHERE sno IN(SELECT Cno FROM sc WHERE grade<60) C: SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade<60 D: SELECT sname FROM s, sc WHERE s.sno=sc.sno OR grade<60

若要求查找“年龄大于18岁学生的学生号和姓名”，正确的SQL语句是( )。 A: SELECT S#，SNAME FROM S WHERE AGE＞18 B: SELECT S#，SNAME FROM S WHERE AGE＞=18 C: SELECT S#，SNAME FROM S WHERE AGE＞’18’ D: SELECT S#，SNAME FROM S WHERE AGE＞=’18’

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#，SNAME FROM S WHERE S# = (SELECT SS# FROM SC WHERE C# = 'C2' ) B: SELECT S#，SNAME FROM S，SCWHERE S# = SS# AND C# = 'C2' C: SELECT S#，SNAME FROM S，SC WHERE S# = SS# AND C# = 'C2' ORDER BY S# D: SELECT S#，SNAME FROM S WHERE S# IN (SELECT SS# FROM SC WHERE C# ='C2' )