多选题以下哪个是一个合法的表名?
多选题在以下的陈述中，哪一个特性与表空间相关? A．总是具有读写状态 B．只由一个操作系统文件组成 C．只有在数据库关闭期间才可以将其置为联机 D．可以由多个数据文件组成，每一个文件可以放在不同的磁盘上
多选题Given that:
Exception is the superclass of IOException and
IOException is the superclass of FileNotFoundException
and
2. import java.io.*;
3. class Author {
4. protected void write() throws IOException { }
5. }
6. public class Salinger extends Author {
7. private void write(int x) { }
8. protected void write (long x) throws FileNotFoundException { }
9. protected void write (boolean x) throws Exception { }
10. protected int write(short x) {return 7; }
11. public void write() { }
12. }
What is the result? (Choose all that apply.)
多选题Given:
2. interface Plant {
3. int greenness = 7;
4. void grow();
5. }
6. class Grass implements Plant {
7. // static int greenness = 5;
8. // int greenness = 5;
9. public static void main(String[] args)
10. int greenness = 2;
11. new Grass().grow();
12. }
13. public void grow() {
14. System.out.println(++greenness);
15. } }
Which are true? (Choose all that apply.)
多选题以下是客户(CUSTOMER)表和客户_订单(CURR_ORDER)表的结构：
CUSTOMER
------------------------------------
CUSTOMER_ID NUMBER(5)
NAME VARCHAR2(25)
CREDIT_LIMIT NUMBER(8, 2)
ACCT_OPEN_DATE DATE
CURR_ORDER
------------------------------------
ORDER_ID NUMBER(5)
CUSTOMER_ID NUMBER(5)
ORDER_DATE DATE
TOTAL NUMBER(8, 2)
以下哪种情况下应该使用子查询来返回所需的结果?
多选题下面哪条语句正确描述了与多段备份相关的动态性能视图和数据字典视图?
多选题Given:
2. public class Later {
3. public static void main(String[] args) {
4. boolean earlyExit = new Later().testl(args);
5. if(earlyExit) assert false;
6. new Later() .test2(args);
7. }
8. boolean test1 (String[] a) {
9. if (a.length == 0) return false;
10. return true;
11. }
12. private void test2(String[] a) {
13. if (a.length == 2) assert false;
14. } }
Which are true? (Choose all that apply.)
多选题以下是INVENTORY(库存)表中每一列的详细定义： Column Name ID_HUMBER DESCRIPTION MANUFACTURER_ID QUANTITY PRICE ORDER_DATE Key Type PK FK Nulls/Unique HN, U NN NN FK Table MANUFACTURER FK Column ID_NUMBER Datatype NUM VARCHAR2 VARCHAR2 NUM HUM DATE Length 9 25 26 9 8, 2 要删除1997年7月25目之后的任何一个指定的库存记录(即具有一个特定标识号码的库存记录)，请问在如下的语句中使用哪个来完成此项操作? A．DELETE FROM inventory WHERE order_date＞'25-JUL-1997' AND id_number= B．DROP FROM inventory WHERE order_date＞TO_DATE('25-JUL-97') AND id_number= C．DELETE FROM inventory WHERE order_date=＞'25-JUL-97' AND id_number=' D．DELETE FROM inventory WHERE order_date＞('25-JUL-1997') OR id_number= E．DELETE FROM inventory WHERE order_date＞TO_DATE('July 25, 1997', 'DD.MM.YYYY') AND id_number=
多选题Given:
2. class SafeDeposit {
3. private static SafeDeposit singleton;
4. public static SafeDeposit getInstance(int code) {
5. if(singleton == null)
6. singleton = new SafeDeposit(code);
7. return singleton;
8. }
9. private int code;
10. private SafeDeposit(int c) { code = c; }
11. int getCode() {return code; }
12. }
13. public class BeSafe {
14. // insert lots of code here
25. }
Which are true? (Choose all that apply.)
多选题在一个查询语句的哪些子句中可以使用替代变量?
多选题Given:
3. public class RediMix extends Concrete {
4. RediMix() {System.out.println("r "); }
5. public static void main(String[] args) {
6. new RediMix();
7. }
8. }
9. class Concrete extends Sand {
10. Concrete() {System.out.print("c ");
11. private Concrete(String s) { }
12. }
13. abstract class Sand {
14. Sand() {System.out.print("s "); }
15. }
What is the result?