关系数据库是(1)的集合,它由一个或多个关系模式定义。SQL语言中的数据定义功能包括对数据库、基本表、(2)和(3)的定义。设有关系Students(学号,姓名,年龄,性别,系名),如果要查询姓名至少包含5个字母,且倒数第二个字母为“G”的学生的学号、姓名以及所在系,则对应的SELECT语句如下:SELECT 学号,姓名,系名FROM Students WHERE(4)LIKE(5);
A.元组 B.列 C.字段 D.表
单项选择题在Windows操作系统中, 回收站 可以恢复()上使用键删除文件或文件夹。
A.软盘 B.硬盘 C.U盘 D.软盘或硬盘
单项选择题若采用短作业优先调度算法,则作业调度次序为()
A.J3→J4→J2→J1 B.J1→J2→J3→J4 C.J1→J3→J4→J2 D.J4→J3→J2→J1
单项选择题某数值编码为FFH,若它所表示的真值为-127,则它是用()表示的。
A.原码 B.反码 C.补码 D.移码
单项选择题On a()memory system,the logical memory space available to the program is totally independent of the physical memory space.
A.cache B.virtual C.RAM D.ROM
单项选择题A programmer must know about a function’s()to call it correctly.
A.location B.algorithm C.interface D.statements
单项选择题One solution to major security problem is(),which are frequently installed to fix known security holes.
A.patches B.compensations C.complements D.additions
单项选择题()is a clickable string or graphic that points to another Web page or document.
A.Link B.Anchor C.Browser D.Hyperlink
单项选择题In()programming, the user determines the sequence of instructions to be executed ,not the programmer.
A.top-down B.structure C.data-driven D.event-driven
单项选择题The standard()in C language contain many useful functions for input and output , string handing,mathematical computations,and system programming tasks.
A.database B.files C.libraries D.subroutine
单项选择题In C language,functions are important because they provide a way to()code so that a large complex program can be written by combining many smaller parts.
A.modify B.modularize C.block D.board