talbe :

pub(pub_code char(2),pub_name varchar2(32))

book(book_code char(8),book_name varhcar2(128),pub_code char92),author_code

char(4),book_mem varchar2(128))

author(author_code char(4),author_name varchar2(10),sex char(1), age

number(3),dir varchar2(64))

auth_list(auth_date date,author_code char(4))

在PL/SQL中有以下两种字义

v_book_row book%rowtype;

v_book_code book.bank_code%type;

请说明v_book_row,v_book_code变量的含义以及数据类型

[试题]The author uses the Philharmonic pub to prove that_______A． Liverpool is a well-known city for its restaurantsB． Liverpool is an impressive place full of attractionC． a pub is a wonderful place for visitors to relax themselvesD． a pub is a perfect cho

[单选题]The author uses the Philharmonic pub to prove that _________.A． Liverpool is a well-known city for its restaurantsB． Liverpool is an impressive place full of attractionC． a pub is a wonderful place for visitors to relax themselvesD． a pub is a perfec

[单选题]C．isco路由器上使用团体字pub向管理站pub.abc.edu.cn发送自陷消息，正确的snmp配置语句是______。A．) snmp-server enable trapssnmp-server host pub.abc.edu.cn pubB．) snmp-server traps enablesnmp-server host pub.abc.edu.cn pubC．) snmp-server enable trapssnmp-server pub.abc.edu.cn pubD．)

[单选题]阅读下面程序class Test implements Runnable{public static void main(String[] args){Test t = new Test();t.start();}public void run(){ }}下列关于上述程序的叙述正确的是A．) 程序不能通过编译，因为 start() 方法在 Test 类中没有定义B．) 程序编译通过，但运行时出错，提示 start() 方法没有定义C．) 程序不能通过编译，因为 run() 方法没有定义方法体D．

[单选题]下列程序的输出结果为( )。 public class Reentrant { public synchronized void a() { b(); System.out.println("here I am, in a()"); } public synchronized void b() { System.out.println("here I am, in b()"); } public static void main(String args[ ]) { Reentrant r

[单选题]Cisco路由器上使用团体字pub向管理站pub.abc.edu.ca发送自陷消息，正确的snmp配置语句是（　　）。A.snmp-serverena

[单选题]Cisco路由器上使用团体字pub向管理站pub.abc.edu.cn发送自陷消息，正确的snmp配置语句是（　　）。A.snmp-serverena

[单选题]下列程序的运行结果是 include class A { int a; public: A( ) {a=0;}A(int aa) {下列程序的运行结果是#include＜iostream.h＞class A{int a;public:A．( ) {a＝0;}A．(int aa){a＝aa;cout ＜ ＜ a＋＋;}};void main( )A． x,y(2) ,z(3) ;cout ＜ ＜ endl;}A．00B．23C．34D．25

[单选题]执行下列程序，输出的结果为( )。 public class Test { public static void main (String[] args) { int a=10； for (int i=1；i＜5；i++) {a+=10；} System. out. println (A)； } }A．20B．30C．40D．50

[单选题]下列代码的执行结果是______。public class Test{public static void main(String[]args){int[]x={0, 1, 2, 3};for(int i=0;i＜3;i+=2){try{System.out println(x[i+23/x[i]+x[i+1]);}catch(ArithmeticException e){System.out.println("error1");}catch (Exception e){System.out