已知表xk(sno,cno,grade),创建规则，限定grade的范围在0-100之间,其正确语句为（ ）
A: create rule gradeRuleas @grade between 0 and 100
B: create gradeRuleas @grade between 0 and 100
C: create rule gradeRuleas grade between 0 and 100
D: create gradeRuleas grade between 0 and 100
A: create rule gradeRuleas @grade between 0 and 100
B: create gradeRuleas @grade between 0 and 100
C: create rule gradeRuleas grade between 0 and 100
D: create gradeRuleas grade between 0 and 100
举一反三
- 在SC表中添加约束，限定成绩Grade的取值范围为0-100，将下面的SQL语句补充完整。正确的选项是（ ）。 Alter Table SC Add CJ （Grade>=0 And Grade<=100）
- 查询编号为'c01'的课程考试成绩在80-89之间的学生的学号,下列（）语句不能实现。 A: select sno ,grade from sc where cno='c01' and grade between 80 and 89 B: select sno ,grade from sc where cno='c01' and grade>=80 and grade<90 C: select sno ,grade from sc where cno='c01' and not (grade90) D: select sno ,grade from sc where cno='c01' and grade in (80-89)
- 在学生选课数据库中，将所有选了课程‘DB’且分数在60~70分之间的学生的成绩增加百分之十，SQL语句为（ ） A: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=’DB’ AND Grade BETWEEN 60 AND 70; B: UPDATE SC SET Grade+=Grade*0.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade >= 60 AND Grade <=70; C: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade <= 60 AND Grade >=70; D: UPDATE SC SET Grade=Grade*1.1 WHERE Cno IN (Select Cno From Course WHERE Cname=’DB’) AND Grade BETWEEN 60 AND 70;
- 在“学生-课程”数据库中，当定义SC表时对字段Grade进行约束：Grade SMALLINT CHECK (Grade>=0 AND Grade<=100)，如果SC表中原有记录('201215121','7',92)，那么当执行"UPDATE SC SET Grade=Grade+10"时，数据库和DBMS将___________。 A: SC表数据不变，DBMS报错不允许更新 B: 记录('201215121','7',92)更新为('201215121','7',100)，DBMS提醒Grade值不能超过100 C: 记录('201215121','7',92)更新为('201215121','7',NULL)，DBMS提醒Grade值不能超过100 D: SC表数据不变，DBMS显示语句语法正确
- 设有关系模式：SC(sno，cno，grade)，各属性含义依次是学号、课程号、分数。要查询分数低于60分的学生学号，正确的SQL语句是______。 A: SEI，ECT sno FROM SC WH ERE grade BETWEEN O AND 60 B: SELECT sno FROM SC WHERE grade＜60 C: SELECT sno FROM SC HAVlNG grade BETWEEN O AND 60 D: SELECT sno FROM SC HAVING grade＜60