oracle 查询测试样题
1.select count(*) from employees where last_name like _A%;key:02.select count(*)from employeeswhere to_char(hire_date,YYYY)=1998;select count(*)from employeeswhere hire_date like %98;key:23select to_char(hire_date,YYYY) from employees;3.se
1. select count(*) from employees where last_name like '_A%'; key:0 2. select count(*) from employees where to_char(hire_date,'YYYY')=1998; select count(*) from employees where hire_date like '%98'; key:23 select to_char(hire_date,'YYYY') from employees; 3. select job_title, max_salary-min_salary as "SAL_DIEF" from jobs order by max_salary-min_salary desc; select job_title,(max_salary-min_salary) as "SAL_DIEF" from jobs order by 2 desc; 19行记录 4. select count(*) from employees where (salary>12000 or salary12000; --当它判断1000为假时就不判断后面的大于12000了. select job_id from employees; select * from employees where job_id in('ST_MAN','SH_CLERK'); --工作岗位名称要加单引号 5. select count(*) from employees where to_char(hire_date,'YYYY')=1999 and to_char(hire_date,'mm')=02; key:3 select count(*) from employees where to_char(hire_date,'YYYY-MM')='1999-02'; 6. select last_name,salary, decode(trunc(salary/1500),0,'A', 1,'B', 2,'C', 'D' ) Grade from employees where last_name like'%s'; 7. select d.department_id,d.department_name,l.city from departments d,locations l where d.department_id in(10,40,90) and d.location_id=l.location_id; 8. select l.city,c.country_name,r.region_name from locations l,regions r,countries c where l.location_id=1000 and l.country_id=c.country_id and c.region_id=r.region_id; 9. select m.last_name "MAN_NAME",nvl(e.last_name,'NO EMPLOYEES') "EMP_NAME" from employees m,employees e where m.department_id=100 and m.employee_id=e.manager_id(+); 10行记录 select m.last_name MAN_NAME,nvl(e.last_name,'NO EMPLOYEES') EMP_NAME from employees m,employees e where m.department_id=100 and m.employee_id=e.manager_id(+); 10 select department_id,count(*) NUM from employees where salary>8000 group by department_id ; 9行记录 11 select department_id,count(*) NUM from employees where salary>5000 group by department_id having count(*)>3; 3行记录 12 select last_name,salary from employees where salary> (select salary from employees where employee_id=110) and department_id=100; 2行记录 13 select count(*) NUM from employees where commission_pct<all distinct commission_pct from employees where salary>12000 and commission_pct is not null ); 24行记录 </all>

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











Solutions to Oracle cannot be opened include: 1. Start the database service; 2. Start the listener; 3. Check port conflicts; 4. Set environment variables correctly; 5. Make sure the firewall or antivirus software does not block the connection; 6. Check whether the server is closed; 7. Use RMAN to recover corrupt files; 8. Check whether the TNS service name is correct; 9. Check network connection; 10. Reinstall Oracle software.

The method to solve the Oracle cursor closure problem includes: explicitly closing the cursor using the CLOSE statement. Declare the cursor in the FOR UPDATE clause so that it automatically closes after the scope is ended. Declare the cursor in the USING clause so that it automatically closes when the associated PL/SQL variable is closed. Use exception handling to ensure that the cursor is closed in any exception situation. Use the connection pool to automatically close the cursor. Disable automatic submission and delay cursor closing.

In Oracle, the FOR LOOP loop can create cursors dynamically. The steps are: 1. Define the cursor type; 2. Create the loop; 3. Create the cursor dynamically; 4. Execute the cursor; 5. Close the cursor. Example: A cursor can be created cycle-by-circuit to display the names and salaries of the top 10 employees.

Oracle views can be exported through the EXP utility: Log in to the Oracle database. Start the EXP utility, specifying the view name and export directory. Enter export parameters, including target mode, file format, and tablespace. Start exporting. Verify the export using the impdp utility.

When Oracle log files are full, the following solutions can be adopted: 1) Clean old log files; 2) Increase the log file size; 3) Increase the log file group; 4) Set up automatic log management; 5) Reinitialize the database. Before implementing any solution, it is recommended to back up the database to prevent data loss.

Oracle is not only a database company, but also a leader in cloud computing and ERP systems. 1. Oracle provides comprehensive solutions from database to cloud services and ERP systems. 2. OracleCloud challenges AWS and Azure, providing IaaS, PaaS and SaaS services. 3. Oracle's ERP systems such as E-BusinessSuite and FusionApplications help enterprises optimize operations.

Building a Hadoop Distributed File System (HDFS) on a CentOS system requires multiple steps. This article provides a brief configuration guide. 1. Prepare to install JDK in the early stage: Install JavaDevelopmentKit (JDK) on all nodes, and the version must be compatible with Hadoop. The installation package can be downloaded from the Oracle official website. Environment variable configuration: Edit /etc/profile file, set Java and Hadoop environment variables, so that the system can find the installation path of JDK and Hadoop. 2. Security configuration: SSH password-free login to generate SSH key: Use the ssh-keygen command on each node

To stop an Oracle database, perform the following steps: 1. Connect to the database; 2. Shutdown immediately; 3. Shutdown abort completely.
