程序员开发人员试题

1、哪一个SQL有错误？A. SELECT * FROM emp_dept_vu;B. SELECT department_id, SUM(salary)FROM emp_dept_vuGROUP BY department_id;C. SELECT department_id, job_id, AVG(salary)FROM emp_dept_vuGROUP BY department_id, job_id;D. SELECT job_id, SUM(salary)FROM emp_dept_vuWHERE department_id IN (10,20)GROUP BY job_idHAVING SUM(salary) > 20000;E. 没有一个错误，都是对的.2、两表结构如下：EMPLOYEES（EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATE）NEW_EMPLOYEES（EMPLOYEE_ID NUMBER Primary KeyNAME VARCHAR2(60)）哪一个删除语句是正确的。

A. DELETE FROM employeesWHERE employee_id = (SELECT employee_id FROM employees);B. DELETE * FROM employeesWHERE employee_id = (SELECT employee_id FROM new_employees);C. DELETE FROM employeesWHERE employee_id IN (SELECT employee_id FROM new_employeesWHERE name ='Carrey');D. DELETE * FROM employeesWHERE employee_id IN (SELECT employee_id FROM new_employeesWHERE last_name ='Carrey');3、显示每个部门，最高SALARY，最小SALARY，且最小SALARY小于5000，最大SALARY大于15000。

A. SELECT dept_id, MIN(salary), MAX(salary)FROM employeesWHERE MIN(salary) < 5000 AND MAX(salary) > 15000;B. SELECT dept_id, MIN(salary), MAX(salary)FROM employeesWHERE MIN(salary) < 5000 AND MAX(salary) > 15000GROUP BY dept_id;C. SELECT dept_id, MIN(salary), MAX(salary)FROM employeesHAVING MIN(salary) < 5000 AND MAX(salary) > 15000;D. SELECT dept_id, MIN(salary), MAX(salary)FROM employeesGROUP BY dept_idHAVING MIN(salary) < 5000 AND MAX(salary) > 15000;E. SELECT dept_id, MIN(salary), MAX(salary)FROM employeesGROUP BY dept_id, salaryHAVING MIN(salary) < 5000 AND MAX(salary) > 15000;4、执行SQL:SELECT * FROM ordersWHERE cust_id = (SELECT cust_id FROM customers WHERE cust_name = 'Smith');5、students表结构如下：STD_ID NUMBER(4)COURSE_ID VARCHAR2(10)START_DATE DATEEND_DATE DATE哪两个在列START_DATE上的运算是正确的？A. SUM(start_date)B. AVG(start_date)C. COUNT(start_date)D. AVG(start_date, end_date)E. MIN(start_date)F. MAXIMUM(start_date)6、EMPLOYEES表结构如下：EMP_ID NUMBER(4) NOT NULLLAST_NAME VARCHAR2(30) NOT NULLFIRST_NAME VARCHAR2(30)DEPT_ID NUMBER(2)哪个SQL语句实现last_name 为‘Smith’不同DEPT_ID的总数？A. SELECT COUNT(*)FROM employeesWHERE last_name='Smith';B. SELECT COUNT(dept_id)FROM employeesWHERE last_name='Smith';C. SELECT DISTINCT(COUNT(dept_id))FROM employeesWHERE last_name='Smith';D. SELECT COUNT(DISTINCT dept_id)FROM employeesWHERE last_name='Smith';E. SELECT UNIQUE(dept_id)FROM employeesWHERE last_name='Smith';7、查询所有employees表中的数据，无论在departments表中是否department_id的记录。

哪个查询是正确的？A. SELECT last_name, department_nameFROM employees NATURAL JOIN departments;B. SELECT last_name, department_nameFROM employees JOIN departments ;C. SELECT last_name, department_nameFROM employees e JOIN departments dON (e.department_id = d.department_id);D. SELECT last_name, department_nameFROM employees eRIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);E. SELECT last_name, department_nameFROM employees FULL JOIN departmentsON (e.department_id = d.department_id);F. SELECT last_name, department_nameFROM employees e LEFT OUTERJOIN departments d ON (e.department_id = d.department_id);8、执行以下SQL，哪个结果是正确的。

SELECT e.employee_id "Emp_id", e.emp_name "Employee", e.salary, m.employee_id "Mgr_id", m.emp_name "Manager"FROM employees e JOIN employees mON (e.mgr_id = m.employee_id)AND e.salary > 4000;9、N表等值联合查询，至少要写几个连接条件？A. NB. N-1C. N+110、哪三个查询没有问题？A. SELECT *FROM employeeswhere salary > (SELECT MIN(salary)FROM employeesGROUP BY department_id);B. SELECT *FROM employeesWHERE salary = (SELECT AVG(salary)FROM employeesGROUP BY department_id);C. SELECT distinct department_idFROM employeesWHERE salary > ANY (SELECT AVG(salary)FROM employeesGROUP BY department_id);D. SELECT department_idFROM employeesWHERE salary > ALL (SELECT AVG(salary)FROM employeesGROUP BY department_id);E. SELECT last_nameFROM employeesWHERE salary > ANY (SELECT MAX(salary)FROM employeesGROUP BY department_id);F. SELECT department_idFROM employeesWHERE salary > ALL (SELECT AVG(salary)FROM employeesGROUP BY AVG(SALARY));判断题：11、Insert into table_1(id,name) values(seq_table_1.nextval,’test’);这条SQL会报错（）12、select * from table_1where create_dt >= to_date(‘2010-01-02 12:23:45’,’yyyy-mm-dd hh:mi:ss’) 这条SQL没有问题 ( )13、查询时使用索引一定能加快查询速度。

（）14、取表中的前40条记录，以下SQL没有问题（）select t.*,rownum rn from( select * from table_1Where create_dt between sysdate - 100 and sysdate order by create_dt desc) twhere rownum <=4015、表table_1中的记录Id name1 aa2 bb3 cc表table_2中的记录ID name2 cc4 dd5 ff执行如下SQL，Select id from table_1UnionSelect id from table_2如果为：ID123245如果正确（）16、表EMPLOYEES如构如下：EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATESelect first_name+last_name from employees; 查询会正常执行（）17、下面SQL没有问题，可以执行（）Select city,sum(sal),max(id),min(first_name),count(*)From table_1Where dept_id = 20Group by city;18、在更新和插入表的数据时，使用绑定变量一定能提高速度（）19、SELECT last_nameFROM employeesWHERE salary IN (SELECT MAX(salary)FROM employeesGROUP BY department_id);此SQL执行时会报错（）20、在select语句中，对查询结果进行排序不会影响查询速度（）21. 下面的网络协议中，面向连接的的协议是：A 传输控制协议B 用户数据报协议C 网际协议D 网际控制报文协议22. 在重新启动Linux系统的同时把存中的信息写入硬盘，应使用命令是：A # rebootB # haltC # reboot nowD # shutdown –r now23. 文件权限读、写、执行的三种标志符号依次是:A rwxB xrwC rdxD srw24. 从后台启动进程，应在命令的结尾加上符号:A &B @C #D $25. crontab文件由六个域组成，每个域之间用空格分割，其排列如下:A MIN HOUR DAY MONTH YEAR COMMANDB MIN HOUR DAY MONTH DAYOFWEEK COMMANDC COMMAND MIN HOUR DAY MONTH DAYOFWEEKD COMMAND YEAR MONTH DAY HOUR MIN26. 某文件的组外成员的权限为只读；所有者有全部权限；组的权限为读与写，则该文件的权限为:A 467B 674C 476D 76427. top命令输出结果 load average: 0.06, 0.03, 0.00 对其0.06, 0.03, 0.00描述正确的是:A 当前负载 5分钟前的负载 15分钟前的负载B 当前负载 1分钟前的负载 5分钟前的负载C 5分钟前的负载 1分钟前的负载当前负载D 15分钟前的负载 5分钟前的负载当前负载28.查看磁盘分区使用情况命令：A lsB llC duD df29.你使用命令“vi /etc/inittab”查看该文件的容，你不小心改动了一些容，为了防止系统出问题，你不想保存所修改容，你应该如何操作:A 在末行模式下，键入:wqB 在末行模式下，键入:q!C 在末行模式下，键入:qD 在编辑模式下，键入“ESC”键直接退出vi30.取文件a.txt里容的第一列下列命令正确的写法是：A awk '{print $1}' a.txtB awk a.txt '{print $1}'C sort –r a.txtD sort –n a.txt31. 使用PS获取当前运行进程的信息时，输出容PPID的含义为：A. 进程的用户IDB. 进程调度的级别C. 进程IDD. 父进程ID32. 为匹配以001开头的行，我们可以使用如下的正则表达式：A. ^001B. $001C. *001D. \00133. 使用nfs服务时，我们需要在_____文件中指定服务容：A. /etc/fstabB. /etc/exportsC. /etc/mountdD. /etc/crontab34. 如果我们先用mount命令加载光驱设备到/mnt/cdrom下，接着我们cd 进入该目录，但用IS列出光盘容后，我们需要换一CD，这时我们需要先执行_____操作。