假設一個無號整數(unsigned short int)占用2 個位元組,執行下列C 語言程式後,會出現什麼結果?#include<stdio.h>int main(){unsigned short int n=64;printf("%x\n", ~n);}
(A)ffff
(B)0000
(C)ffdf
(D)ffbf
有兩個資料表,license 儲存所有證照的基本資料,student 則是儲存所有學生們已經考上的證照資料,license的主鍵為license_id,也是student 的外來鍵,建立資料表的SQL 指令如下:CREATE TABLE license (license_id INT PRIMARY KEY, license_category VARCHAR(20) NOT NULL,licensing_units VARCHAR(50) NOT NULL, license_name VARCHAR(100) NOT NULL, series VARCHAR(50)NOT NULL, count INT NOT NULL );CREATE TABLE student (student_id VARCHAR(10) DEFAULT NULL,name VARCHAR(10) NOT NULL, year INT NOT NULL, semester INT NOT NULL,date DATE NOT NULL, license_id INT,CONSTRAINT ______________________ )請問在填空位置內,正確的設定外來鍵的語法為何?
(A)FK1 FOREIGN KEY (license_id) REFERENCES license (license_id)
(B)FOREIGN KEY (license_id) REFERENCES license_id
(C)FK1 FOREIGN KEY (license_id) REFERENCES license_id
(D)FOREIGN KEY (student) REFERENCES license (license_id)
下列 SQL 指令是用來僅刪除資料表quota 裡面所有資料列,請問何者正確?
(A)REMOVE FROM quota
(B)DROP FROM quota
(C)TRUNCATE TABLE quota
(D)DELETE quota
欲將B 資料表的所有紀錄(record)裡面的A 欄位(資料型別為文數字)內容全部改為C 值,下列的UPDATE指令何者正確?
(A)UPDATE A SET B = 'C'
(B)UPDATE SET B = 'C'
(C)UPDATE B SET A = 'C'
(D)UPDATE ALL B SET A = 'C'
下列名詞與原文的對照關係,何者錯誤?
(A)SQL: structured query language
(B)DML: data manipulation language
(C)DBA: database administrator
(D)QBE: query by excel
已知資料表order 包含下列資料:(各欄位資料型別均為INT)PriceQty100350200250202003030040400若執行下列陳述:SELECT SUM (Price * Qty) FROM order WHERE Qty > 300,問此陳述之回傳值為何?
(A)51000
(B)60000
(C)90000
(D)114000
下列SELECT 結合UNION 指令的語法,何者錯誤?SELECT Name, Address, City FROM Table1 WHERE City='臺北' ORDER BY CityUNIONSELECT Name, Address, City FROM Table2 WHERE City='新北市' ORDER BY City
(A)第一個SELECT 中,不必ORDER BY 子句
(B)每個SELECT 中,不允許有WHERE 子句
(C)每個SELECT 的結果,必須有相同數目的欄位數
(D)合併後的欄位會以第一個SELECT 子句的欄位名稱為主
下列何者不可能是網際網路(IPv4)封包的表頭含選項(header and option)長度?
(A)18B
(B)20B
(C)56B
(D)60B
下列何者不是NIST(National Institute of Standards and Technology)所定義的「雲端運算」規範?
(A)隨需應變自助服務(On-demand Self-service)
(B)網路使用無所不在(Broad Network Access)
(C)軟體即服務(Software as a Service)
(D)快速重新佈署靈活度(Rapid Elasticity)