多选题Given:
2. class Grandfather {
3. static String name = "gf ";
4. String doStuff() {return "grandf "; }
5. }
6. class Father extends Grandfather {
7. static String name = "fa ";
8. String doStuff() {return "father "; }
9. }
10. public class Child extends Father {
11. static String name = "ch ";
12. String doStuff() {return "child "; }
13. public static void main(String[] args) {
14. Father f = new Father();
15. System.out.print(((Grandfather)f).name + ((Grandfather)f) .doStuff());
16. Child c = new Child();
17. System. out.println(((Grandfather) c) .name + ((Grandfather)c) .doStuff() + ((Father)c) .doStuff());
18. } }
What is the result? (Choose all that apply.)
多选题评估如下的SQL*Plus命令： SPOOL dog.1st 这一SQL*Plus命令将产生哪个结果? A．它将查询的结果存入DOG.LST文件 B．它将执行存储在DOG.LST文件中的命令 C．它将存储在DOG.LST文件中的内容存入SQL缓冲区 D．它将把DOG.LST文件的输出内容送到系统打印机
多选题Given:
2. interface Gadget {
3. int patent = 12345;
4. Gadget doStuff();
5. }
6. public class TimeMachine implements Gadget {
7. int patent = 34567;
8. public static void main(String[] args) {
9. new TimeMachine().doStuff();
10. }
11. TimeMachine doStuff() {
12. System.out.println( ++patent);
13. return new TimeMachine();
14. } }
If javac is invoked twice:
javac -source 1.4 TimeMachine.Java
javac TimeMachine. java
And, if"java TimeMachine" is invoked whenever TimeMachine compiles, what is the result?
多选题Given:
3. public class OffRamp {
4. public static void main(String[] args) {
5. int [] exits = {0,0,0,0,0,0};
6. int x1 = 0;
7.
8. for(int x = 0; x ＜ 4; x++) exits[0] = x;
9. for(int x = 0; x ＜ 4; ++x) exits[1] = x;
10.
11. x1 = 0; while(x1++ ＜ 3) exits[2] = x1;
12. x1 = 0; while(++x1 ＜ 3) exits[3] = x1;
13.
14. x1 = 0; do {exits[4] = x1; } while(x1++ ＜ 7);
15. x1 = 0; do {exits[5] = x1; } while(++x1 ＜ 7);
16.
17. for(int x: exits)
18. System.out.print(x + " ");
19. } }
What is the result?
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? DEFINE enroll_date_2='01-JUN-1999' SELECT * FROM student WHERE enroll_date=('&enroll_date_2') / A．去掉&符号 B．去掉单引号 C．在DEFINE命令中将变量说明为DATE数据类型 D．将DEFINE命令以'ACCEPT enroll_date_2 DATE'取代
多选题以下是PRODUCT表和SHIPPING COST表的结构：
PRODUCT
---------------------------------
PRODUCT_ID NUMBER(9)
PRODUCT_NAME VARCHAR2(20)
COST NUMBER(5, 2)
RETAIL_PRICE NUMBER(5, 2)
WEIGHT NUMBER(5, 2)
SHIPPING_COST
---------------------------------
ID NUMBER(9)
LOWWEIGHT NUMBER(5, 2)
HIGHWEIGHT NUMBER(5, 2)
COST NUMBER(5, 2)
如果需要显示包括了每个产品运输价格(shipping cost)的产品名(product name)，而运输价格是通过比较SHIPPING COST表中产品重量的下限和上限来计算的。现在请问，应使用如下查询语句中的哪两个语句?
多选题Given this code in a method:
3. int y, count = 0;
4. for(int x = 3; x ＜ 6; x++) {
5. try {
6. switch(x) {
7. case 3: count++;
8. case 4: count++;
9. case 7: count++;
10. case 9: {y = 7 / (x - 4); count += 10; }
11. }
12. } catch (Exception ex) {count++; }
13. }
14. System.out.println(count);
What is the result?
A. 2
B. 15
C. 16
D. 25
E. 26
F Compilation fails.
G. An exception is thrown with no other output.
多选题在移动表空间DOG_DATA中数据文件的步骤中，以下哪一个是正确的? A．将表空间置为脱机→使用ALTER TABLESPACE RENAME DATAFILE语句，利用操作系统命令移动数据文件→将该表空间重新置为联机 B．使用ALTER TABLESPACE RENAME DATAFILE语句→将表空间置为脱机→利用操作系统命令移动数据文件→将该表空间重新置为联机 C．将表空间置为脱机→利用操作系统命令移动数据文件→将该表空间重新置为联机→使用ALTER TABLESPACE RENAME DATAFILE语句 D．将表空间置为脱机→利用操作系统命令移动数据文件→使用ALTER TABLESPACE RENAME DATAFILE语句→将该表空间重新置为联机
多选题Given the following method signatures from ArrayList:
boolean add(E e)
protected void removeRange (int fromIndexInclusive, int toIndexExclusive)
int size()
and given:
2. import java.util.*;
3. public class MyUtil extends ArrayList {
4. public static void main(String[] args) {
5. MyUtil m = new MyUtil();
6. m.add("w"); m.add("x"); re.add("y"); m.add("z");
7. m.removeRange (1, 3);
8. System.out.print(m.size() + " ");
9. MyUtil m2 = new MyUtil2().go();
10. System.out.println(m2.size());
11. }
12. }
13. class MyUtil2{
14. MyUtil go() {
15. MyUtil m2 = new MyUtil();
16. m2.add("1"); m2.add("2"); m2.add("3");
17. m2.removeRange(1, 2);
18. return m2;
19. } }
What is the result?
多选题以下哪个运算将返回一个数字值?
多选题Given:
3. public class Baskin {
4. public static void main(String[] args)
5. int i = 4;
6. int j = 1;
7.
8. assert (i ＞ Integer.valueOf(args[0]));
9. assert(j ＞ Integer.valueOf(args[0])): "error 1";
10. assert(j ＞ i): "error 2": "passed";
11. } }
And, if the code compiles, given the following two command-line invocations:
Ⅰ. java -ea Baskin 2
Ⅱ. java -ea Baskin 0
Which are true? (Choose all that apply.)
多选题Given:
3. public class Dec26 {
4. public static void main(String[] args)
5. short a1 = 6;
6. new Dec26() .go(a1);
7. new Dec26() .go(new Integer(7));
8. }
9. void go(Short x) {System.out.print("S "); }
10. void go(Long x) {System.out.print("L "); }
11. void go(int x) {System.out.print("i "); }
12. void go(Number n) {System.out.print("N ");
13. }
What is the result?
多选题Given:
2. public class Maize {
3. public static void main(String[] args) {
4. String s = "12";
5. s.concat ("ab");
6. s = go(s);
7. System.out.println(s);
8. }
9. static String go(String s)
10. s.concat("56");
11. return s;
12. } }
What is the result?
多选题Given:
3. public class Gauntlet {
4. public static void main(String[] args) {
5. String r = "0";
6. int x = 3, y = 4;
7. boolean test = false;
8. if((x ＞ 2) || (test = true))
9. if((y ＞ 5) || (++x == 4))
10. if((test == true) || (++y == 4))
11. r += "i";
12. else if(y == 5) r += "2";
13. else r += "3";
14. else r += "4";
15. // else r += "5";
16. System.out.println(r);
17. } }
And given that, if necessary you can add line 15 to make the code compile, what is the result? (Choose all that apply.)
多选题以下是CLASS表中的数据： CLASS CLASS_ID CLASS_NAME HOURS_CREDIT INSTRUCTOR_ID 1 Incroduction to Accouncting 3 4 2 Computer Basics 3 1 3 Tax Accouncing Principles 3 4 4 American History 3 2 5 Basic Engineering 3 请评估如下的SQL语句，当使用这个查询语句查询数据库时将显示以下哪个值? SELECT COUNT(instructor_id) FROM class; A．2 B．3 C．4 D．5 E．这个语句将不会成功地执行
多选题以下哪个查询语句将返回一个数字值? A．SELECT order_date/7 FROM inventory; B．SELECT (order_date+366/24) FROM inventory; C．SELECT (SYSDATE, order_date)/7 FROM inventory; D．SELECT (SYSDATE-order_date)/7 FROM inventory;
多选题Given:
2. public class Skip {
3. public static void main(String[] args) throws Exception {
4. Thread t1 = new Thread(new Jump());
5. Thread t2 = new Thread(new Jump());
6. t1.start(); t2.start();
7. t1.join(500);
8. new Jump() .run();
9. } }
10. class Jump implements Runnable {
11. public void run() {
12. for(int i = 0; i ＜ 5; i++) {
13. try {Thread.sleep(200); }
14. catch (Exception e) {System.out.print("e "); }
15. System.out.print(Thread.currentThread() .getId() + "-" + i+ " ");
16. } } }
What is the result?
多选题以下的哪一个表应该创建一个位图索引? A．LINN_ITEM表的大小有10GB，而且这个表分布在许多个不同的表空间中 B．SHIPPING表包括了数千记录，而且它由一个联机事务处理系统访问，并且更新操作非常频繁 C．TRANS_DETAIL表包含了900多万行数据，索引关键字的列为“high cardinality”，而且表的更新操作非常频繁 D．Employee表包含了1000多万行数据，索引关键字的列为“low cardinality”，而且从这个表中抽取数据的查询绝大多数使用了带有多个OR操作符的组合WHERE子句
多选题一个追踪文件中存储了什么? A．数据块崩溃的错误 B．有关后台进程的信息 C．最近的全备份的日期和时间 D．在实例启动时所使用的非默认的初始化参数
多选题以下哪个SQL命令将删除视图PARTS_VU? A．DROP parts_vu; B．DELETE parts_vu; C．DROP VIEW parts_vu; D．DELETE VIEW parts_vu;