本文中，將會包含部分我做過的Orcale習題，以供參考，希望能有熱心的小夥伴，積極討論，歡迎指出錯誤，或更好的解決方法~
一、Orcale 經典習題-40題
資料庫的結構和資料都在我上傳的資源中，可以進行免費下載。（本來想免費的，結果設定不了免費，至少1分，就設定成了1分 0.0）
題目&我做的答案

--1.查詢僱傭時間在1997年之後的員工資訊
Select
    *
From
    employees e
Where
    1997 < extract(year from e.hire_date) ;

--2.查詢有提成的員工資訊（last name,  job, salary, and commission），並按工資降序排列。
 

Select 
    last_name,  job_id, salary,  e.commission_pct
From
    employees e
Order by
    3 desc;      

--3.Show the employees that have no commission with a 10% raise in their salary 
--(round off the salaries).
-- 向沒有佣金的員工展示他們的工資增加10％（四捨五入的薪水）。
Select 
    employee_id, first_name, last_name, salary, 
    round(nvl2(commission_pct, salary, salary * 1.10
 
), 0) new_salary
From
    employees e
Where
    commission_pct is null;   

--4.Show the last names of all employees together with the number of years 
--and the number of completed months that they have been employed.
--顯示所有員工的姓氏以及他們被僱用的年數和完成月數。
With 
    Q_mon As (Select employee_id, extract(month from
 
 sysdate)-extract(month from hire_date) mon_diff From employees)
Select 
    last_name,
    case when mon_diff >= 0  then (extract(year from sysdate) - extract(year from hire_date)) else
         (extract(year from sysdate) - extract(year from hire_date) - 1)  end work_year,
    case when mon_diff >= 0 then mon_diff else (mon_diff + 12) end work_month
From 
    employees e, Q_mon
Where 
    e.employee_id = Q_mon.employee_id;

--5. Show those employees that have a name starting with J, K, L, or M
--顯示名稱以J，K，L或M開頭的員工
Select * From employees Where first_name like 'J%'
union all
Select * From employees Where first_name like 'K%' 
union all
Select * From employees Where first_name like 'L%'
union all
Select * From employees Where first_name like 'M%';
--Select * From employees Where regexp_like(first_name,'^[J|K|L|M].*');

--6.Show all employees, and indicate with “Yes” or “No” whether they receive a commission.
--顯示所有員工，並在“是”或“否”時表明他們是否收到佣金。
Select 
    employee_id, first_name, last_name, 
    case when commission_pct is null then 'NO' else 'YES' end  whether     
From
    employees e;

--7.Show the department names, locations, names, job titles, 
--and salaries of employees who work in location 1800.
--在1800位置顯示工作的員工的部門名稱，地點，姓名，職位和工資。
Select
    d.department_name, d.location_id, e.first_name, e.last_name, e.job_id, e.salary
From
    employees e, departments d 
Where 
    e.department_id = d.department_id and d.location_id = 1800;

--8.How many employees have a name that ends with an n? Create two possible solutions.
--有多少員工的名字以n結尾？ 建立兩個可能的解決方
Select 
    count(last_name)
From 
    employees
Where 
    last_name like '%n';

Select 
    sum(decode(substr(last_name, -1), 'n', 1, 0)) sum_number
From 
    employees;

Select 
    count(last_name)
From 
    employees
Where 
    regexp_like(last_name,'.*n$');


--9.Show the names and locations for all departments, 
--and the number of employees working in each department. 
--Make sure that departments without employees are included as well.
--顯示所有部門的名稱和位置，以及每個部門的員工數量。 確保包含沒有員工的部門。
Select
    d.department_id, d.department_name, d.location_id, count(employee_id)
From
    departments d left join employees e on d.department_id = e.department_id
Group by
    d.department_id, d.department_name, d.location_id      
Order by 
    1 ;     

--10.Which jobs are found in departments 10 and 20?
--在部門10和20中找到哪些工作？
Select 
    job_id
From 
    employees e
Where
    e.department_id = 10
Union
Select 
    job_id
From 
    employees e
Where
    e.department_id = 20; 

--11.Which jobs are found in the Administration and Executive departments, 
--and how many employees do these jobs? Show the job with the highest frequency first.
--在行政和執行部門找到了哪些工作，有多少員工從事這些工作？ 首先顯示頻率最高的作業。
Select 
    job_id, count(employee_id)
From
    employees e  left join departments d on e.department_id = d.department_id 
Where
    upper(d.department_name) in (upper('Administration'), upper('Executive'))
Group by
    job_id
Order by
    2 desc; 

--12.Show all employees who were hired in the first half of the month (before the 16th of the month).
--顯示在本月上半月（本月16日之前）被僱用的所有員工。
Select employee_id, last_name, hire_date 
From employees e
Where extract(day from hire_date) < 16;  

--13. Show the names, salaries, and the number of dollars (in thousands) that all employees earn.
--顯示所有員工的姓名，賺取的工資和美元數（以千計）。
Select 
    first_name, last_name, to_char(salary, 'L9,999,000,00') 
From
    employees e;

--14.Show all employees who have managers with a salary higher than $15,000. 
--Show the following data: employee name, manager name, manager salary, and salary grade of the manager.
--顯示所有經理薪水高於15,000美元的員工。 顯示以下資料：員工姓名，經理姓名，經理薪水和工資等級。
Select 
    e.first_name ||' '||e.last_name employee_name, 
    e1.first_name ||' '||e1.last_name manager_name,
    e1.salary,  (case when e1.salary < 5000 then 'A'
                      when e1.salary < 10000 then 'B'
                      when e1.salary < 15000 then 'C'
                      when e1.salary < 20000 then 'D'
                      else  'E' end) salary_level
From 
    employees e left join  employees e1 on e1.employee_id = e.manager_id
Where 
    e1.salary > 15000 ; 

--15. Show the department number, name, number of employees, and average salary of all departments,
-- together with the names, salaries, and jobs of the employees working in each department.
--顯示所有部門的部門編號，姓名，員工人數和平均工資，以及每個部門工作人員的姓名，工資和工作。
Select 
    d.department_id , department_name, 
    /*(select count(*) From employees e 
     Where e.department_id = d.department_id Group by e.department_id) sum_number, 
    (Select Round( avg(salary), 2) From employees e1 
     Where e1.department_id = d.department_id Group by e1.department_id) avg_salary,*/
    count(*) over (partition by e2.department_id) sum_number,
    Round( avg(salary) over (partition by e2.department_id), 2 ) avg_salary,
    last_name, salary, job_id
From 
    departments d left join employees e2 on d.department_id = e2.department_id;

Select 
    nvl2(lag(d.department_id, 1, null) over (partition by e2.department_id order by null),null, d.department_id),
    nvl2(lag(d.department_name, 1, null) over (partition by d.department_name order by null),null, d.department_name),
--    nvl2(lag(), 1, null) 
--    over (partition by (count(*) over (partition by e2.department_id)) order by null),null, d.department_id),
    d.department_id , department_name,   
    count(*) over (partition by e2.department_id) sum_number,
    Round( avg(salary) over (partition by e2.department_id), 2 ) avg_salary,
    last_name, salary, job_id
From 
    departments d left join employees e2 on d.department_id = e2.department_id ;    


select 
    decode ( lag(t1.A ,1,null) over (partition by t1.A order by t1.A,t1.B,t1.C,t1.D),null,t1.A,null) A1,
    decode ( lag(t1.B ,1,null) over (partition by t1.A order by t1.A,t1.B,t1.C,t1.D),null,t1.B,null) A2,
    decode ( lag(t1.C ,1,null) over (partition by t1.A order by t1.A,t1.B,t1.C,t1.D),null,t1.C,null) A3,
    decode ( lag(t1.D ,1,null) over (partition by t1.A order by t1.A,t1.B,t1.C,t1.D),null,t1.D,null) A4,
t1.E,t1.F,t1.G
from 
(select distinct d.department_id  A ,
        d.department_name B,
       count(e.employee_id) over (partition by e.department_id ) as C,
      -- nvl2(avg(e.salary) over (partition by e.department_id ),to_char(),'no average')  as D,       
       nvl (to_char(avg(e.salary) over (partition by e.department_id ),'999,999,999.99'),'no average') as D,
       e.last_name as E,
       e.salary as F ,
       e.job_id as G
from departments d,employees e
where d.department_id=e.department_id(+))  t1;    
--使用 lag 進行置空    

--16.Show the department number and the lowest salary of the department with the highest average salary.
--顯示平均工資最高的部門編號和最低工資。
With
    Q1 as (Select department_id, avg(salary) avg_salary From employees Group by department_id)
Select 
    distinct e.department_id, min(salary) over(partition by e.department_id) min_salary
From
    employees e left join  Q1 on e.department_id = Q1.department_id
Where
    avg_salary >= (Select max(Q1.avg_salary) From Q1); 

--17.Show the department numbers, names, 
--and locations of the departments where no sales representatives work.
--顯示沒有銷售代表工作的部門的部門編號，名稱和位置。                        
Select 
    distinct d.department_id, d.department_name, d.location_id, d.manager_id
From 
    departments d left join employees e on d.manager_id = e.manager_id
    left join jobs j on e.job_id = j.job_id
Where 
    NVL2(j.job_title, upper(j.job_title), 'title_null') <> upper('Sales Representative') 
Order by 
    1;                          

--18.Show the department number, department name, and the number of employees working in each department that:
--a.  Includes fewer than 3 employees:    b.  Has the highest number of employees:   
--c.  Has the lowest  number of employees: 
--18.   顯示部門名稱、編號、工作在每個部門的員工數量，分別有以下三個要求
--a小於三個員工   b員工數最多   c員工數最少                          
With
    Q1 AS (Select d.department_id, count(employee_id) sum_number 
           From departments d left join employees e on d.department_id = e.department_id
           Group by d.department_id)     
Select 
    department_name, d.department_id, sum_number
From  
    departments d left join Q1 
    on d.department_id = q1.department_id
Where 
     --q1.sum_number < 3   
     --q1.sum_number >= (Select max(sum_number) From Q1 )
     q1.sum_number <= (Select min(sum_number) From Q1);
--需要 departments 與 employees 做 左外連結 ！！！

--19.  Show the employee number, last name, salary, department number, 
--and the average salary in their department for all employees.
--顯示所有員工的員工編號，姓氏，工資，部門編號以及部門的平均工資。
Select 
    e.employee_id, first_name || ' ' ||last_name employee_name, e.department_id, 
    Round(avg(e.salary)over(partition by e.department_id) , 2)  depart_salary_avg
From
    employees e;

--20.Show all employees who were hired on the day of the week 
--on which the highest number of employees were hired.                          
--顯示在僱用最多僱員人數的當天僱用的所有員工。
With                                         
    Q1 as (Select to_char(hire_date, 'DAY','NLS_DATE_LANGUAGE=AMERICAN') hire_day, count(employee_id) hire_sum
           From employees e1
           Group by to_char(hire_date, 'DAY','NLS_date_language=american')
           Order by 2 Desc)            
Select 
   first_name, last_name, to_char(hire_date, 'DAY','NLS_date_language=american') hire_day
From
   employees e1 
Where
   to_char(hire_date, 'DAY','NLS_date_language=american') in 
   (Select hire_day From Q1 Where Q1.hire_sum >= (Select max(hire_sum) From Q1)) ;

--21.Create an anniversary overview based on the hire date of the employees. 
--Sort the anniversaries in ascending order.
--根據員工的僱用日期建立週年紀念概覽。 按升序排列週年紀念日。 
Select 
    first_name, last_name,to_char(hire_date, 'mm-dd') birth_hire
From
    employees e
Order by
    3 ASC; 

Select localtimestamp From dual;
--22.Find the job that was filled in the first half of 1990 
--and the same job that was filled during the same period in 1991.
--找到1990年上半年填補的工作和1991年同期填補的工作。
Select 
    job_id 
From 
    employees 
Where 
    extract(year from hire_date) = 1990 
    and extract(month from hire_date) <= 6 
Intersect 
Select 
    job_id 
From 
    employees 
Where 
    extract(year from hire_date) = 1991 
    and extract(month from hire_date) <= 6 

--23.. Write a compound query to produce a list of employees showing raise percentages, 
--employee IDs, and old salary and new salary increase. 
--Employees in departments 10, 50, and 110 are given a 5% raise, 
--employees in department 60 are given a 10% raise, 
--employees in departments 20 and 80 are given a  15% raise, 
--and employees in department 90 are not given      a raise.    
--23.  顯示工資漲幅，員工編號，原來的工資和增加的工資： 
--部門號10、50、110的有5%的漲幅，部門號為60的漲10%的工資
--部門號為20和80漲幅為15%，部門為90的不漲工資
Select 
    e1.department_id, salary_by, employee_id, salary, salary * (1 + salary_by)
From 
    employees e1 left join 
    (Select department_id, 
     decode(department_id, 10,0.05, 50,0.05, 100,0.05, 60,0.10, 20,0.15, 80,0.15, 0 )salary_by
     From employees
     Group by department_id) s on e1.department_id = s.department_id
Order by 
    2 desc;  

--24.Alter the session to set the NLS_DATE_FORMAT to  DD-MON-YYYY HH24:MI:SS.
Select * from nls_session_parameters Where parameter = 'NLS_DATE_FORMAT';   --'DD-MON-RR'
Select sysdate From dual;
Alter session Set NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';

--25the following time zones.
--a. Australia/Sydney    Chile/Easter Island 
SELECT TZ_OFFSET ('Australia/Sydney') from dual; 
SELECT TZ_OFFSET ('Chile/EasterIsland') from dual; 

--b. Alter the session to set the TIME_ZONE parameter value to the time zone offset of Australia/Sydney.
--alter session set time_zone = '+10:00'; 
Alter session set time_zone = 'Australia/Sydney';  
Select SYSDATE, CURRENT_DATE, CURRENT_TIMESTAMP, LOCALTIMESTAMP From dual;

--c. Display the SYSDATE, CURRENT_DATE, CURRENT_TIMESTAMP, and LOCALTIMESTAMP for this session. 
--Note: The output might be different based on the date when the command is executed.
SELECT SYSDATE,CURRENT_DATE, CURRENT_TIMESTAMP, LOCALTIMESTAMP FROM DUAL; 

--d. Alter the session to set the TIME_ZONE parameter value to the time zone offset of Chile/Easter Island.
--alter session set time_zone = '-6:00'; 
Alter session set time_zone = 'Chile/EasterIsland';
Select SYSDATE, CURRENT_DATE, CURRENT_TIMESTAMP, LOCALTIMESTAMP From dual;

--e. Display the SYSDATE, CURRENT_DATE, CURRENT_TIMESTAMP, and LOCALTIMESTAMP for this session. 
Select SYSDATE, CURRENT_DATE, CURRENT_TIMESTAMP, LOCALTIMESTAMP From dual;

--f. Alter the session to set the NLS_DATE_FORMAT to  DD-MON-YYYY.
Alter session Set NLS_DATE_FORMAT = 'DD-MON-YYYY';

Select * from nls_session_parameters;
Select * from nls_database_parameters;
Select * from nls_instance_parameters;


--26.Write a query to display the last names, month of the date of join, and hire date 
--of those employees who have joined in the month of January, irrespective of the year of join.
--寫一個查詢來顯示姓氏，加入日期和僱用日期？ 無論加入年份如何，在1月份加入的員工。  
With
    Q1 as (Select 
               count(*) sum_number, to_char(e.hire_date, 'yyyy-mm') year_mon 
           From 
               employees e  Group by to_char(e.hire_date, 'yyyy-mm')) 
Select 
    last_name,
    sum_number, 
    hire_date
From
    employees e left join Q1
    on to_char(e.hire_date, 'yyyy-mm') = Q1.year_mon
Where
    1 = extract(month from hire_date);     

--27.Write a query to display the following for those departments 
--whose department ID is greater    than 80:
--The total salary for every job within a department 
--The total salary  
--The total salary for those cities in which the departments are located
--The total salary for every job, irrespective of the department 
--The total salary for every department irrespective of the city
--The total salary of the cities in which the departments are located
--Total salary for the departments, irrespective of  job titles and cities 
--編寫查詢以顯示部門ID更高的部門的以下內容？ 比80：
--部門內每項工作的總薪水
--總薪水
--各部門所在城市的總薪資
--每個工作的總薪水，不論部門如何
--不論城市如何，每個部門的總薪水
--各部門所在城市的總薪資
--各部門的總薪資，不論職稱和城市
Select 
    city, department_name, job_id, sum(salary)
From
    employees e, departments d, locations l
Where
    l.location_id = d.location_id and d.department_id = e.department_id
    and d.department_id > 80
Group by 
    cube(city, department_name, job_id) 
Order by
    1, 2, 3;

--28.. Write a query to display the following groupings:
--Department ID, Job ID
--Job ID, Manager ID 
-- The query should calculate the maximum and minimum salaries for each of these groups.
--編寫查詢以顯示以下分組：
--部門ID，職務ID
--工作ID，經理ID
-- 查詢應計算每個組的最高和最低工資。 
Select
    department_id, job_id, manager_id, max(salary), min(salary)
From
    employees e
Group by 
    --rollup(department_id, manager_id, job_id)
    grouping sets((department_id, job_id),(job_id, manager_id))
Order by 
    1,2,3;  

--29.Write a query to display the top three earners in the EMPLOYEES table.
-- Display their last   names and salaries.
--編寫查詢以顯示EMPLOYEES表中的前三個收入者。 顯示他們的姓氏和工資。 
Select 
    last_name,salary  
From 
    (Select rownum r1 , last_name, salary From employees Order by 3 desc) Q
Where
    r1 < 4;
--使用分析函式    


--30.Write a query to display the employee ID and last names of the employees 
--who work in the state of California. 
--編寫查詢以顯示在加利福尼亞州工作的員工的員工ID和姓氏。
Select 
    employee_id, last_name
From
    employees e, departments d, locations l
Where
    e.department_id = d.department_id and d.location_id = l.location_id
    and upper(l.state_province) = upper('California'); 

--31. Write a query to delete the oldest JOB_HISTORY row of  an employee 
--by looking up the     JOB_HISTORY table for the MIN(START_DATE) for the employee. 
--Delete the records of     only those employees who have changed at least two jobs.
--If your query executes correctly,     you will get the feedback:
--編寫查詢以通過查詢員工的MIN（START_DATE）的JOB_HISTORY表來刪除員工的最舊JOB_HISTORY行。 
--僅刪除已更改至少兩個作業的員工的記錄。 如果您的查詢正確執行，您將獲得反饋：
Delete From
    job_history j    
--Select j.*   From job_history j
Where
   /* j.employee_id = (Select Q1.employee_id
                     From (Select employee_id, count(employee_id) change_time
                           From job_history j1
                           Group by employee_id
                           Having count(employee_id) > 1) Q1
                     Where Q1.employee_id = j.employee_id)

    and */
    j.start_date = (Select min(j2.start_date)
                    From job_history j2
                    Where j2.employee_id = j.employee_id
                    having count(*) >= 2);
rollback;

--32.Roll back the transaction.
Select job_id, job_title, min_salary, max_salary
From Jobs
Order by 4 desc;

Insert into jobs(job_id, job_title, min_salary, max_salary)
Values('My_job', 'My_title', 15000.00, 30000.00);
Savepoint insert_jobs;

Update jobs 
Set min_salary = 20000.00, max_salary = 50000.00
Where job_id = 'My_job';
Savepoint update_jobs;
rollback to savepoint insert_jobs;

Update jobs 
Set min_salary = 45000.00, max_salary = 60000.00
Where job_id = 'My_job';
Savepoint update_jobs1;
rollback to savepoint update_jobs;

Insert into jobs(job_id, job_title, min_salary, max_salary)
Values('My_job1', 'My_title1', 15000.00, 30000.00);
Savepoint insert_jobs1;

rollback to savepoint update_jobs;
rollback to savepoint update_jobs1;
rollback ;
commit;

--33.Write a query to display the job IDs of those jobs 
--whose maximum salary is above half the    maximum salary in the whole company. 
--Use the WITH clause to write this query. Name the     query MAX_SAL_CALC.
--編寫查詢以顯示最高工資高於整個公司最高工資一半的工作的工作ID。 
--使用WITH子句編寫此查詢。 將查詢命名為MAX_SAL_CALC。
With 
    Job_salary_max As (Select job_id, max(salary) job_max From employees Group by job_id),
    All_salary_max As (Select max(salary) * 0.50 Half_all From employees)
Select 
    job_title, job_max
From 
    Job_salary_max,All_salary_max,jobs
Where 
    Job_salary_max.job_id = jobs.job_id and Job_salary_max.job_max > All_salary_max.Half_all;

--34.Write a SQL statement to display employee number, last name, start date, and salary,showing:
--a. De Haan’s direct reports   --b. The organization tree under De Haan (employee number 102)
--編寫一個SQL語句來顯示員工編號，姓氏，開始日期和工資：
--De Haan 的領導，  --手下的員工
Select 
    employee_id, first_name, last_name, hire_date, salary
From
    employees e
Start with
    upper(last_name) = upper('De Haan')
Connect by
--employee_id = prior manager_id;
    prior employee_id =  manager_id;

--35.   Write a hierarchical query to display the employee number, manager number, 
--and employee last name for all employees who are two levels below employee De Haan 
--(employee number 102). Also display the level of the employee.
--編寫分層查詢以顯示員工De Haan（員工編號102）以下兩級員工的員工編號，
--經理編號和員工姓氏。還顯示員工的級別。
Select *
From (
Select 
    employee_id, first_name, last_name, manager_id, level employee_levles
From
    employees e
Start with
    upper(last_name) = upper('De Haan')
Connect by
    prior employee_id =  manager_id
)
Where 
    employee_levles > 2;

--36.   Produce a hierarchical report to display the employee number, manager number, 
--the LEVEL pseudocolumn, and employee last name. For every row in the EMPLOYEES table, 
--you should print a tree structure showing the employee, the employee’s manager, 
--then the manager’s manager, and so on. Use indentations for the NAME column. 
--生成分層報告以顯示員工編號，經理編號，LEVEL偽列和員工姓氏。 
--對於EMPLOYEES表中的每一行，您應該列印一個樹結構，顯示員工，員工的經理，
--然後是經理的經理，等等。 對NAME列使用縮排。
Select 
    employee_id, manager_id, level, Lpad(last_name, length(last_name)-1+level, '_' ) level_name
From
    employees e
Start with
    employee_id = 100
Connect by
    prior employee_id =  manager_id;

select employee_id, manager_id,
       level, lpad(last_name, length(last_name) + level - 1, '_')
from employees e
start with employee_id in
            (select employee_id
             from employees
             start with manager_id is null
             connect by manager_id = prior employee_id)
connect by e.employee_id = prior e.manager_id;


--37.Write a query to do the following: 
--Retrieve the details of the employee ID, hire date, salary, and manager ID 
--of those employees whose employee ID is more than or equal to 200 from the EMPLOYEES table.
--If the salary is less than $5,000, insert the details of employee ID and salary into the SPECIAL_SAL table.
--Insert the details of employee ID, hire date, and salary into the SAL_HISTORY table. 
--Insert the details of employee ID, manager ID, and salary into the MGR_HISTORY table.
--37.   顯示員工編號、入職時間、薪水、上司的編號，要求員工編號大於等於200
   --如果薪水小於5000，將員工編號和薪水插入到SPECIAL_SAL表裡
   --將員工編號、入職時間、薪水插入到SAL_HISTORY表
   --將員工編號、上司編號、薪水插入到MGR_HISTORY表
Create table 
    special_sal(employee_id number primary key, salary number)
Create table
    sal_history(employee_id number primary key, hire_date date not null, salary number)
Create table
    mgr_history(employee_id number primary key, manager_id number, salary number)    

Insert all 
    When salary < 5000 then into special_sal values(employee_id, salary)
    When 1 = 1 then into sal_history values(employee_id, hire_date, salary)
    When 1 = 1 then into mgr_history values(employee_id, manager_id, salary)
Select 
    employee_id, hire_date, salary, manager_id
From
    employees
Where
    employee_id >= 200;   

Select * From special_sal;
Select * From sal_history;   
Select * From mgr_history;  
rollback;  

--38.Query the SPECIAL_SAL, SAL_HISTORY and the MGR_HISTORY tables to view the inserted records.
--查詢SPECIAL_SAL，SAL_HISTORY和MGR_HISTORY表以檢視插入的記錄。
Select * From special_sal;
Select * From sal_history;   
Select * From mgr_history; 

--39.Create the LOCATIONS_NAMED_INDEX table based on the following table instance chart.    
--Name the index for the PRIMARY KEY column as LOCATIONS_PK_IDX.
--39.   基於下列示意圖建立一個LOCATIONS_NAMED_INDEX表，將主鍵列作為索引並起名為LOCATIONS_PK_IDX
Create table 
    locations_named_index (Deptno number(4) constraint locations_pk_idx primary key, 
                           Dname varchar2(30) );
select 
    t.*,i.index_type 
from 
    user_ind_columns t,user_indexes i 
where 
    t.index_name = i.index_name and t.table_name= Upper('locations_named_index');

drop table locations_named_index;

--40.Query the USER_INDEXES table to display the INDEX_NAME for the LOCATIONS_NAMED_INDEX table. 
--
Select 
    index_name 
From 
    USER_INDEXES 
Where 
    tabele_name = 'LOCATIONS_NAMED_INDEX';