发布时间 : 星期六 文章ORACLE数据库选择题更新完毕开始阅读bdbee7d649649b6648d74744
1.下面语句错误的原因是:
Update departments set department_id=300 where department_id=60; ERROR 位于第 1 行:
ORA-02292: 违反完整约束条件 (HR.EMP_DEPT_FK) - 已找到子记录日志 A.where条件语法错误
B.违反主键约束,department_id为300的记录已经存在
C.60号部门下已经有员工,修改60号部门编号将违反完整性约束条件 D.60号部门不存在
答案:C
2.下面创建表的语句错在哪里 CREATE TABLE abc AS
Select last_name, salary*12 From employees; A.CREATE TABLE abc B.AS
C.Select last_name, salary*12 D.From employees;
答案:C
3.下列关于主键说法正确的是: A.一个表只允许一个主键 B.一个表可以有多个主键
C.数据库会为主键自动创建对应的唯一索引 D.主键只表示该字段不允许为空 答案:AC
4.下面能修改表名字的命令是: A.ALTER TABLE RENAME B.RENAME
C.ALTER TABLE MOVE D.ALTER TABLE MODIFY
答案:B
5.下面那个SQL命令是用于清空表中数据的DDL语句: A.UPDATE B.DELETE C.TRUNCATE D.SELECT
答案:C
6.下面哪条语句可以取出薪水最高的前三个人:
A.select * from (select * from employees order by salary );
B.select * from (select * from employees order by salary ) where rownum<=3; C.select * from (select * from employees order by salary desc) where rownum<=3; D.select * from employees where rownum<=3 order by salary desc; 答案:C
7.下面那个权限是连接数据库所需要的权限: A.create table B.create session C.create tablespace D.create database
答案:B
8.下面哪种情况会使没有完成的事务“隐式”提交: A.执行多个查询语句 B.执行Commit
C.执行create table 命令 D.服务器掉电
答案:C
9.表 CLASSES 和 表 SCHEDULE 结构如下: CLASSES:
ID NUMBER(9)
CLASS_NAME VARCHAR2(20) TEACHER_ID NUMBER(9) SCHEDULE:
CLASS_TIME DATE CLASS_ID NUMBER(9)
你建一个视图显示每一课的课名、课时,并按教师ID排序 判断下面语句将返回何种结果? CREATE VIEW class_schedule AS
SELECT C.class_name as “Name”, s.class_time FROM classes c, schedule s
WHERE C.id = s.class_id ORDER BY teacher_id;
A.语句创建视图 CLASS_SCHEDULE 且可产生预期结果. B.“Name”别名有语法错误
C.语法错误,因为视图不可基于连接查询.
D.语法错误,因为视图不可包含 ORDER BY 子句.
答案:A
10.表TEACHER 包含如下字段: 列名 可为空否? 数据类型
TEACHER_ID NOT NULL NUMBER(9) NAME VARCHAR2(25) SALARY NUMBER(7,2)
SUBJECT_ID NOT NULL NUMBER(5) SUBJECT_DESCRIPTION VARCHAR2(2)
你需要将理科教师的工资上浮8%,理科教师的SUBJECT_ID是011,你需用哪一句实现? A.UPDATE teacher salary = salary * 1.08 WHERE subject_id = 011
B.UPDATE teacher SET salary = salary *1 .08 WHERE subject_id == 011 C.UPDATE teacher SET salary = salary * 1.08 WHERE subject_id = 011
D.UPDATE teacher SET salary = salary *1 .08 WHERE subject_id like ‘1%’ 11.哪句可以实现显示 id_number 和 description ,条件满足订单时间order_date在 January 1, 1997 以前的,且单价price小于 1.00 或者大于 5.00 的, 结果用订单时间降序排列。 A.SELECT id_number, description FROM inventory WHERE (price < 1.00 OR price > 5.00)
AND order_date < to_date('yyyy-mm-dd','1997-01-01') ORDER BY order_date DESC;
B.SELECT id_number, description FROM inventory WHERE (price < 1.00 OR price > 5.00)
AND order_date < to_date('yyyy-mm-dd','1997-01-01') ORDER BY order_date;
C.SELECT id_number, description FROM inventory WHERE (price < 1.00 OR price > 5.00 )
AND order_date < to_date('1997-01-01','yyyy-mm-dd') ORDER BY order_date ASC;
D.SELECT id_number, description FROM inventory WHERE (price <1.00 OR price > 5.00)
AND order_date < to_date('1997-01-01','yyyy-mm-dd') ORDER BY order_date DESC;
答案:D
12.哪一子句可实现 SELECT 语句查询员工平均工资小于5000的部门信息 ? A.GROUP BY dept_id WHERE AVG(sal) < 5000 B.GROUP BY AVG(sal) HAVING AVG(sal) < 5000 C.GROUP BY dept_id HAVING AVG(sal) < 5000 D.GROUP BY AVG(sal) < 5000
答案:C
13.试图使用下面句子查询数据:
SELECT 100/NVL(quantity, 0) FROM inventory;
QUANTITY为 null 空值时,将导致出错,其原因是? A.除数表达式为空值.
B.函数参数数据类型不一致. C.空值不能被转成实际值 D.除数表达式为零. 答案:D
14.下列哪个集合操作符返回两个查询所选择的所有的行。 A.Union B.Union all C.Union only D.connect by
答案:B
15.有如下SQL片段
Delete from emp e where e.hiredate>’14-Dec-09’and e.sal <> ‘1’其含义为:
A.从表emp中删除hiredate 不小于2009年12月14日,且sal不为1的记录,一定不可恢复
B.从表emp中删除hiredate 和 sal列
C.对表emp中hiredate不小于2009年12月14日,且sal不为1的记录实施删除 D.删除emp表的全部记录
答案:C
16.SQL语言中修改表结构的命令是? A.MODIFY TABLE
B.MODIFY STRUCTURE C.ALTER TABLE
D.ALTER STRUCTURE
答案:C
17.Delete和 truncate 都可以用来删除表内容,以下描述正确的是? A.Truncate 不需要 rollbacksegment B.Delete 需要rollbacksegment
C.Truncate在 提交commit之前仍可回滚 D.Truncate还可以删除表结构
答案:AB