多选题以下是EMPLOYEE表的详细定义，其中也包括了约束的描述。 EMPLOYEE Column Name EMPLOYEE_ID NAME JOB MANAGER DATE_HIRED SALARY BONUS DEPIARTMENT_ID Key-Type PK Nulls/Unique NN，U NN NN FK Table FK Column Datatype HUM VARCHAR2 VARCHAR2 NUM DATE NUM HUM NUM Length 6 20 9 6 7, 2 7, 2 2 基于这个EMPLOYEE表创建了一个视图，并允许用户通过这个视图向EMPLOYEE表中插入数据。请问，在如下的语句中，应该使用哪个语句创建这个视图? A．CREATE VIEW department_v AS SELECT DISTINCT department FROM employee; B．CREATE VIEW emp_info_v AS SELECT employee_id, name, job, manager FROM employee; C．CREATE VIEW emp_info_v AS SELECT employee_id, name, job, manager, department_id, date_hired FROM employee; D．CREATE VIEW dept_salary_v AS SELECT department_id，AVG (salary) "average salary" FROM employee GROUP BY department_id;
多选题Given:
1. import java.util.*;
2. public class Elway {
3. public static void main(String[] args) {
4. ArrayList[] ls = new ArrayList[3];
5. for(int i = 0; i ＜ 3; i++) {
6. ls[i] = new ArrayList();
7. ls[i].add("a" + i);
8. }
9. Object o = ls;
10. do3(ls) ;
11. for(int i = 0; i ＜ 3; i++) {
12. // insert code here
13. }
14. }
15. static Object do3(ArrayList[] a) {
16. for(int i = 0; i ＜ 3; i++) a[i] .add("e");
17. return a;
18. } }
And the following fragments:
Ⅰ. System.out.print (o [i ] + " ");
Ⅱ. System.out.print((ArrayList[]) [i] + " ");
Ⅲ. System.out.print( ((Object[])o) [i] + " ");
Ⅳ. System.out.print(((ArrayList[])o) [i] + " ");
If the fragments are added to line 12, independently, which are true? (Choose all that apply.)
多选题要显示赋予概要文件DOG_PROJECT的资源限制信息，请问应该查询如下哪一个数据字典? A．DBA_USERS B．DBA_TABLES C．DBA_OBJECTS D．DBA_PROFILES E．DBA_TABLESPACE
多选题哪一个Oracle服务器的组件是由后台进程和内存结构所组成的? A．SGA B．一个实例(instance) C．一个重做日志文件 D．一个数据库文件
多选题如果需要创建多路复用备份集，那么使用一个BACKUP命令最多可以为每个备份段创建多少个副本?
多选题完整恢复不重要的数据文件时，下面的哪些步骤不是必需的?
多选题Given:
2. public class Toolbox {
3. static Toolbox st;
4. public static void main(String[] args) {
5. new Toolbox().go();
6. // what"s eligible?
7. }
8. void go() {
9. MyInner in = new MyInner();
10. Integer i3 = in.doInner();
11. Toolbox t = new Toolbox();
12. st = t;
13. System.out.println(i3);
14. }
15. class MyInner {
16. public Integer doInner() {return new Integer(34);
17. }
18. }
When the code reaches line 6, which are eligible for garbage collection? (Choose all that apply.)
多选题以下是学生(STUDENT)表所包含的全部列的定义： ID NUMBER(9) PK LAST_NAME VARCHAR2(25) FIRST_NAME VARCHAR2(25) ENROLL_DATE DATE 请看如下的SQL脚本(语句)，应该怎样修改才可以使它运行? ACCEPT id 'Please enter the student id: ' SELECT id, last_name, first_name, enroll_date FROM student WHERE id=&id / A．修改ACCEPT命令 B．在SELECT子句中添加一列 C．在ACCEPT命令中定义一个数据类型 D．将单引号改成双引号
多选题使用下面的语句创建了一个新用户：
SQL＞grant connect, resource
2＞to c##bob identified by bob container=all;
Grant succeeded.
SQL＞connect c##bob/bob;
Connected.
SQL＞select pdb_id, pdb_name, con_id from cdb_pdbs;
no rows selected
既然C##是一个公共用户，为什么在CDB_PDBS中看不到任何行?
多选题请看以下创建表的语句：
CREATE TABLE customer (
customer_id NUMBER,
company_id VARCHAR2(30),
contact_name VARCHAR2(30),
contact_title VARCHAR2(20),
address VARCHAR2(30),
city VARCHAR2(25),
region VARCHAR2(10),
postal_code VARCHAR2(20),
country_id NUMBER DEFAULT 25,
phone VARCHAR2(20),
fax VARCHAR2(20),
credit_limit NUMBER(7, 2));
以上这个DDL语句将完成如下哪3个商业要求?
多选题创建3个RMAN会话，来备份3个不同的表空间。第三个RMAN会话运行这条命令：
run{
set command id to "user bkup";
backup tablespace users;
}
对于这个命令，V$SESSION.CLIENT_INFO列的值是什么?
多选题使用如下的SQL语句查询数据库： SELECT bonus FROM salary WHERE bonus BETWEEN 1 AND 250 OR (bonus IN (190, 500, 600) AND bonus BETWEEN 250 AND 500); 请问这个SQL语句将返回如下的哪个值? A．100 B．260 C．400 D．600
多选题应该使用如下哪个命令显示视图PARTS_VU的结构? A．DESCRIBE pats_vu B．DESCRIBE user_views C．SELECT * FROM user_views WHERE lower (view)=parts_vu; D．SELECT * FROM user_objects WHERE lower (user_view)=parts_vu;
多选题在以下有关备份控制文件的论述中，哪两个是正确的? A．应该在创建一个表空间之后备份控制文件 B．如果数据文件是多重映像的(冗余的)，不需要备份控制文件 C．应该在向一个现有的数据库中添加一个数据文件之后备份控制文件 D．使用ALTER DATABASE BACKUP CONTROLFILE TO TRACE语句将创建一个控制文件的操作系统备份
多选题Given:
3. public class Drip extends Thread {
4. public static void main(String[] args) {
5. Thread t1 = new Thread(new Drip());
6. t1.start();
7. t1.join();
8. for(int i = 0; i ＜ 1000; i++) // Loop #1
9. System.out.print(Thread.currentThread() .getName() + " ");
10. }
11. public void run() {
12. for(int i = 0; i ＜ 1000; i++) // Loop #2
13. System.out.print(Thread.currentThread() .getName() + " ");
14. } }
Which are true? (Choose all that apply.)
多选题Given the proper import statements and:
23. try {
24. File file = new File("myFile.txt");
25. PrintWriter pw = new PrintWriter(file);
26. pw.println("line 1");
27. pw.close();
28. PrintWriter pw2 = new PrintWriter("myFile.txt");
29. pw2.println("line 2");
30. pw2.close();
31. } catch (IOException e) { }
What is the result? (Choose all that apply.)
多选题要创建一个报表，这个报表将显示那些信用限额大于所有客户平均信用限额的客户，应使用如下的哪个查询语句? A．SELECT last_name, first_name FROM customer WHERE credit_limit＞AVG(credit_limit); B．SELECT last_name, first_name, AVG(credit_limit) FROM customer GROUP BY AVG(credit_limit); C．SELECT last_name, firs_name, AVG(credit_limit) FROM customer GROUP BY AVG(credit_limit) HAVING credit_limit＞AVG(credit_limit); D．SELECT last_name, first_name FROM customer WHERE credit_limit＞(SELECT AVG(credit_limit) FROM customer); E．SELECT last_name, first_name FROM customer WHERE credit_limit=(SELECT AVG(credit_limit) FROM customer);
多选题Given two files:
1. package com;
2. public class MyClass {
3. public static void howdy() {System.out.print("howdy "); }
4. public static final int myConstant = 343;
5. public static final MyClass mc = new MyClass();
6. public int instVar = 42;
7. }
11. import static com. MyClass.*;
12. public class TestImports {
13. public static void main(String[] args)
14. System.out.print(myConstant + " ");
15. howdy();
16. System.out.print(mc.instVar + " ");
17. System.out.print(instVar + " ");
18. } }
What is the result? (Choose ALL that apply.)
多选题在以下有关数据库备份的描述中找到不正确的描述。
多选题在一个SELECT语句中，应该使用WHERE子句来完成以下的哪些工作? A．指定INVENTORY表的位置(地址) B．将MANUFACTURER_ID的值与897898进行比较 C．仅显示MANUFACTURER_ID的值 D．限制SUM(price)函数的输出