SQL / SQLPlus Interview Questions
SQL / SQLPlus Interview Questions
1. How can variables be passed to a SQL routine?
Expected answer: By use of the & symbol. For passing in variables the numbers
1-8 can be used (&1, &2,...,&8) to pass the values after the command into the
SQLPLUS session. To be prompted for a specific variable, place the ampersanded
variable in the code itself:
"select * from dba_tables where owner=&owner_name;" . Use of double
ampersands tells SQLPLUS to resubstitute the value for each subsequent
use of the variable, a single ampersand will cause a reprompt for the
value unless an ACCEPT statement is used to get the value from the user.
2. You want to include a carriage return/linefeed in your output from a SQL script, how can you do this?
Expected answer: The best method is to use the CHR() function (CHR(10) is a return/linefeed) and the concatenation function "". Another method, although it is hard to document and isn?t always portable is to use the return/linefeed as a part of a quoted string.
3. How can you call a PL/SQL procedure from SQL?
Expected answer: By use of the EXECUTE (short form EXEC) command.
4. How do you execute a host operating system command from within SQL?
Expected answer: By use of the exclamation point "!" (in UNIX and some other OS) or the HOST (HO) command.
5. You want to use SQL to build SQL, what is this called and give an example
Expected answer: This is called dynamic SQL. An example would be:
set lines 90 pages 0 termout off feedback off verify off
spool drop_all.sql
select ?drop user ?username? cascade;? from dba_users
where username not in ("SYS?,?SYSTEM?);
spool off
Essentially you are looking to see that they know to include a command (in this case DROP USER...CASCADE;) and that you need to concatenate using the ?? the values selected from the database.
6. What SQLPlus command is used to format output from a select?
Expected answer: This is best done with the COLUMN command.
7. You want to group the following set of select returns, what can you group on?
Max(sum_of_cost), min(sum_of_cost), count(item_no), item_no
Expected answer: The only column that can be grouped on is the "item_no" column, the rest have aggregate functions associated with them.
8. What special Oracle feature allows you to specify how the cost based system treats a SQL statement?
Level: Intermediate to high Expected answer: The COST based system allows the use of HINTs to control the optimizer path selection. If they can give some example hints such as FIRST ROWS, ALL ROWS, USING INDEX, STAR, even better.
9. You want to determine the location of identical rows in a table before attempting to place a unique index on the table, how can this be done?
Level: High Expected answer: Oracle tables always have one guaranteed unique column, the rowid column. If you use a min/max function against your rowid and then select against the proposed primary key you can squeeze out the rowids of the duplicate rows pretty quick. For example: select rowid from emp e where e.rowid > (select min(x.rowid) from emp x where x.emp_no = e.emp_no); In the situation where multiple columns make up the proposed key, they must all be used in the where clause.
10. What is a Cartesian product?
Expected answer: A Cartesian product is the result of an unrestricted join of two or more tables. The result set of a three table Cartesian product will have x * y * z number of rows where x, y, z correspond to the number of rows in each table involved in the join.
11. You are joining a local and a remote table, the network manager complains about the traffic involved, how can you reduce the network traffic?
Level: High Expected answer: Push the processing of the remote data to the remote instance by using a view to pre-select the information for the join. This will result in only the data required for the join being sent across.
12. What is the default ordering of an ORDER BY clause in a SELECT statement?
Expected answer: Ascending
13. What is tkprof and how is it used?
Level: Intermediate to high Expected answer: The tkprof tool is a tuning tool used to determine cpu and execution times for SQL statements. You use it by first setting timed_statistics to true in the initialization file and then turning on tracing for either the entire database via the sql_trace parameter or for the session using the ALTER SESSION command. Once the trace file is generated you run the tkprof tool against the trace file and then look at the output from the tkprof tool. This can also be used to generate explain plan output.
14. What is explain plan and how is it used?
Level: Intermediate to high Expected answer: The EXPLAIN PLAN command is a tool to tune SQL statements. To use it you must have an explain_table generated in the user you are running the explain plan for. This is created using the utlxplan.sql script. Once the explain plan table exists you run the explain plan command giving as its argument the SQL statement to be explained. The explain_plan table is then queried to see the execution plan of the statement. Explain plans can also be run using tkprof.
15. How do you set the number of lines on a page of output? The width?
Level: Low Expected answer: The SET command in SQLPLUS is used to control the number of lines generated per page and the width of those lines, for example SET PAGESIZE 60 LINESIZE 80 will generate reports that are 60 lines long with a line width of 80 characters. The PAGESIZE and LINESIZE options can be shortened to PAGES and LINES.
16. How do you prevent output from coming to the screen?
Level: Low
Expected answer: The SET option TERMOUT controls output to the screen. Setting TERMOUT OFF turns
off screen output. This option can be shortened to TERM.
17. How do you prevent Oracle from giving you informational messages during and after a SQL statement execution?
Level: Low Expected answer: The SET options FEEDBACK and VERIFY can be set to OFF.
18. How do you generate file output from SQL?
Answer: By use of the SPOOL command
1. How can variables be passed to a SQL routine?
Expected answer: By use of the & symbol. For passing in variables the numbers
1-8 can be used (&1, &2,...,&8) to pass the values after the command into the
SQLPLUS session. To be prompted for a specific variable, place the ampersanded
variable in the code itself:
"select * from dba_tables where owner=&owner_name;" . Use of double
ampersands tells SQLPLUS to resubstitute the value for each subsequent
use of the variable, a single ampersand will cause a reprompt for the
value unless an ACCEPT statement is used to get the value from the user.
2. You want to include a carriage return/linefeed in your output from a SQL script, how can you do this?
Expected answer: The best method is to use the CHR() function (CHR(10) is a return/linefeed) and the concatenation function "". Another method, although it is hard to document and isn?t always portable is to use the return/linefeed as a part of a quoted string.
3. How can you call a PL/SQL procedure from SQL?
Expected answer: By use of the EXECUTE (short form EXEC) command.
4. How do you execute a host operating system command from within SQL?
Expected answer: By use of the exclamation point "!" (in UNIX and some other OS) or the HOST (HO) command.
5. You want to use SQL to build SQL, what is this called and give an example
Expected answer: This is called dynamic SQL. An example would be:
set lines 90 pages 0 termout off feedback off verify off
spool drop_all.sql
select ?drop user ?username? cascade;? from dba_users
where username not in ("SYS?,?SYSTEM?);
spool off
Essentially you are looking to see that they know to include a command (in this case DROP USER...CASCADE;) and that you need to concatenate using the ?? the values selected from the database.
6. What SQLPlus command is used to format output from a select?
Expected answer: This is best done with the COLUMN command.
7. You want to group the following set of select returns, what can you group on?
Max(sum_of_cost), min(sum_of_cost), count(item_no), item_no
Expected answer: The only column that can be grouped on is the "item_no" column, the rest have aggregate functions associated with them.
8. What special Oracle feature allows you to specify how the cost based system treats a SQL statement?
Level: Intermediate to high Expected answer: The COST based system allows the use of HINTs to control the optimizer path selection. If they can give some example hints such as FIRST ROWS, ALL ROWS, USING INDEX, STAR, even better.
9. You want to determine the location of identical rows in a table before attempting to place a unique index on the table, how can this be done?
Level: High Expected answer: Oracle tables always have one guaranteed unique column, the rowid column. If you use a min/max function against your rowid and then select against the proposed primary key you can squeeze out the rowids of the duplicate rows pretty quick. For example: select rowid from emp e where e.rowid > (select min(x.rowid) from emp x where x.emp_no = e.emp_no); In the situation where multiple columns make up the proposed key, they must all be used in the where clause.
10. What is a Cartesian product?
Expected answer: A Cartesian product is the result of an unrestricted join of two or more tables. The result set of a three table Cartesian product will have x * y * z number of rows where x, y, z correspond to the number of rows in each table involved in the join.
11. You are joining a local and a remote table, the network manager complains about the traffic involved, how can you reduce the network traffic?
Level: High Expected answer: Push the processing of the remote data to the remote instance by using a view to pre-select the information for the join. This will result in only the data required for the join being sent across.
12. What is the default ordering of an ORDER BY clause in a SELECT statement?
Expected answer: Ascending
13. What is tkprof and how is it used?
Level: Intermediate to high Expected answer: The tkprof tool is a tuning tool used to determine cpu and execution times for SQL statements. You use it by first setting timed_statistics to true in the initialization file and then turning on tracing for either the entire database via the sql_trace parameter or for the session using the ALTER SESSION command. Once the trace file is generated you run the tkprof tool against the trace file and then look at the output from the tkprof tool. This can also be used to generate explain plan output.
14. What is explain plan and how is it used?
Level: Intermediate to high Expected answer: The EXPLAIN PLAN command is a tool to tune SQL statements. To use it you must have an explain_table generated in the user you are running the explain plan for. This is created using the utlxplan.sql script. Once the explain plan table exists you run the explain plan command giving as its argument the SQL statement to be explained. The explain_plan table is then queried to see the execution plan of the statement. Explain plans can also be run using tkprof.
15. How do you set the number of lines on a page of output? The width?
Level: Low Expected answer: The SET command in SQLPLUS is used to control the number of lines generated per page and the width of those lines, for example SET PAGESIZE 60 LINESIZE 80 will generate reports that are 60 lines long with a line width of 80 characters. The PAGESIZE and LINESIZE options can be shortened to PAGES and LINES.
16. How do you prevent output from coming to the screen?
Level: Low
Expected answer: The SET option TERMOUT controls output to the screen. Setting TERMOUT OFF turns
off screen output. This option can be shortened to TERM.
17. How do you prevent Oracle from giving you informational messages during and after a SQL statement execution?
Level: Low Expected answer: The SET options FEEDBACK and VERIFY can be set to OFF.
18. How do you generate file output from SQL?
Answer: By use of the SPOOL command
Useful Oracle Queries
Select ename, sal, sal*12 "Annual Salary" from EMP order by "Annual Salary" desc;
2) Display name, salary, Hra, pf, da, TotalSalary for each employee. The out put should be in the order of total salary, hra 15% of salary, DA 10% of salary .pf 5% salary Total Salary will be (salary+hra+da)-pf?
Select ename, sal SA, sal*0.15 HRA, sal*0.10 DA, sal*5/100 PF, sal+ (sal*0.15) + (sal*0.10) -(sal*.05) TOTALSALARY from emp ORDER BY TOTALSALARY DESC;
3) Display Department numbers and total number of employees working in each Department?
Select deptno, count (*) from emp group by deptno;
4) Display the various jobs and total number of employees working in each job group?
Select job, count (*) from emp group by job;
5) Display department numbers and Total Salary for each Department?
Select deptno, sum (sal) from emp group by deptno;
6) Display department numbers and Maximum Salary from each Department?
Select deptno, max (Sal) from emp group by deptno;
7) Display various jobs and Total Salary for each job?
Select job, sum (sal) from emp group by job;
8)Display each job along with min of salary being paid in each job group?
Select job, min (sal) from emp group by job;
9) Display the department Number with more than three employees in each department?
Select deptno, count (*) from emp group by deptno having count (*)>3;
10) Display various jobs along with total salary for each of the job where total salary is greater than 40000?
Select job, sum (sal) from emp group by job having sum (Sal)>40000;
11) Display the various jobs along with total number of employees in each job. The output should contain only those jobs with more than three employees?
Select job, count (*) from emp group by job having count (*)>3;
12) Display the name of employees who earn Highest Salary?
select ename, sal from emp where sal>=(select max(sal) from emp );
13) Display the employee Number and name for employee working as clerk and earning highest salary among the clerks?
select ename,empno from emp where sal=(select max(sal) from emp where job='CLERK') and job='CLERK' ;
14) Display the names of salesman who earns a salary more than the Highest Salary of the Clerk?
select ename,sal from emp where sal>(select max(sal) from emp where job='CLERK') AND job='SALESMAN';
15) Display the names of clerks who earn a salary more than the lowest Salary of any Salesman?
select ename,sal from emp where sal>(select min(sal) from emp where job='SALESMAN') and job='CLERK';
16) Display the names of employees who earn a salary more than that of jones or that of salary greater than that of scott?
select ename,sal from emp where sal>all(select sal from emp where ename='JONES' OR ename='SCOTT');
17) Display the names of employees who earn Highest salary in their respective departments?
select ename,sal,deptno from emp where sal in (select max(sal) from emp group by deptno);
18) Display the names of employees who earn Highest salaries in their respective job Groups?
select ename,job from emp where sal in (select max(sal) from emp group by job);
19)Display employee names who are working in Accounting department?
select e.ename,d.dname from emp e,dept d where e.deptno=d.deptno and d.dname = 'ACCOUNTING';
20) Display the employee names who are Working in Chicago?
select e.ename,d.loc from emp e,dept d where e.deptno=d.deptno and d.loc='CHICAGO';
21) Display the job groups having Total Salary greater than the maximum salary for Managers?
select job ,sum(sal) from emp group by job having sum(sal) >(select max(sal) from emp where job='MANAGER');
22) Display the names of employees from department number 10 with salary greater than that of ANY employee working in other departments?
select ename,deptno from emp where sal>any(select min(sal) from emp where deptno!=10 group by deptno) and deptno=10 ;
23) Display the names of employees from department number 10 with salary greater than that of ALL employee working in other departments?
select ename,deptno from emp where sal>all(select max(sal) from emp where deptno!=10 group by deptno) and deptno=10 ;
24) Display the names of Employees in Upper Case?
select upper(ename) from emp;
25) Display the names of employees in Lower Case?
select Lower(ename) from emp;
26) Display the names of employees in Proper case?
select InitCap(ename)from emp;
27) Find the length of your name using Appropriate Function?
select lentgh('RAMA') from dual;
28) Display the length of all the employee names?
select length(ename) from emp;
29) Display the name of employee Concatinate with Employee Number?
select ename' 'empno from emp;
30) Use appropriate function and extract 3 characters starting from 2 characters from the following string 'Oracle' i.e., the out put should be ac?
select substr('Oracle',3,2) from dual;
31) Find the first occurance of character a from the following string Computer Maintenance Corporation?
select lstr('Computer Maintenance Corporation','a' ) from dual;
32) Replace every occurance of alphabet A with B in the string .Alliens (Use Translate function)
select translate('Alliens','A','B') from Dual;
33) Display the information from the employee table . where ever job Manager is found it should be displayed as Boss?
select ename ,replace(job,'MANAGER','BOSS') from emp;
34) Display empno,ename,deptno from emp table. Instead of display department numbers display the related department name(Use decode function)?
select empno,ename,deptno,Decode(deptno,10,'ACCOUNTING',20, 'RESEARCH' ,30 , 'SALES','OPERATIONS')DName from emp;
35) Display your Age in Days?
select sysdate-to_date('30-jul-1977') from dual;
36) Display your Age in Months?
select months_between(sysdate,to_date('30-jul-1977')) from dual;
37) Display current date as 15th August Friday Nineteen Nienty Seven?
select To_char(sysdate,'ddth Month Day year') from dual;
39) Scott has joined the company on 13th August ninteen ninety?
select empno,ename,to_char(Hiredate,'Day ddth Month year') from emp;
40) Find the nearest Saturday after Current date?
select next_day(sysdate,'Saturday') from dual;
41) Display the current time?
select To_Char(sysdate,'HH:MI:SS') from dual;
42) Display the date three months before the Current date?
select Add_months(sysdate,-3) from dual
43) Display the common jobs from department number 10 and 20?
select job from emp where job in (select job from emp where deptno=20) and deptno=10;
44) Display the jobs found in department 10 and 20 Eliminate duplicate jobs?
select Distinct job from emp where deptno in(10,20);
45) Display the jobs which are unique to department 10?
select job from emp where deptno=10;
46) Display the details of those employees who do not have any person working under him?
select empno,ename,job from emp where empno not in (select mgr from emp where mgr is not null );
47) Display the details of those employees who are in sales department and grade is 3?
select e.ename,d.dname,grade from emp e,dept d ,salgrade where e.deptno=d.deptno and dname='SALES' and grade=3
48) Display thoes who are not managers?
select ename from emp where job!='MANAGER';
49) Display those employees whose name contains not less than 4 characters?
Select ename from emp where length (ename)>=4
50) Display those department whose name start with"S” while location name ends with "K"?
Select e.ename, d.loc from emp e, dept d where d.loc like ('%K') and enamelike ('S%')
51) Display those employees whose manager name is Jones?
Select e.ename Superior, e1.ename Subordinate from emp e, e1 where e.empno = e1.mgr and e.ename='JONES'
52) Display those employees whose salary is more than 3000 after giving 20% increment?
Select ename, sal, (sal+(sal*0.20)) from emp where (sal+(sal*0.20))>3000;
53) Display all employees with their department names?
Select e.ename, d.dname from emp e, dept d where e.deptno=d.deptno
54) Display ename who are working in sales department?
Select e.ename, d.dname from emp e, dept d where e.deptno=d.deptno and d.dname='SALES'
55) Display employee name, dept name, salary, and commission for those sal in between 2000 to 5000 while location is Chicago?
Select e.ename, d.dname, e.sal, e.comm from emp e, dept d where e.deptno=d.deptno and sal between 2000 and 5000
56) Display those employees whose salary is greater than his manager’s salary?
Select e.ename, e.sal, e1.ename, e1.sal from emp e, e1 where e.mgr=e1.empno and e.sal>e1.sal
57) Display those employees who are working in the same dept where his manager is work?
Select e.ename, e.deptno, e1.ename, e1.deptno from emp e, e1 where e.mgr=e1.empno and e.deptno=e1.deptno
58) Display those employees who are not working under any Manager?
Select ename from emp where mgr is null;
59) Display the grade and employees name for the deptno 10 or 30 but grade is not 4 while joined the company before 31-DEC-82?
Select ename, grade, deptno, sal from emp, salgrade where (grade, Sal) in (select grade, Sal from salgrade, emp where sal between losal and hisal) and grade! =4 and deptno in (10,30) and hiredate<'31-Dec-82'
60) Update the salary of each employee by 10% increment that are not eligible for commission?
Update emp set sal= (sal+(sal*0.10)) where comm is null
61) Delete those employees who joined the company before 31-Dec-82 while their department Location is New York or Chicago?
Select e.ename, e.hiredate, d.loc from emp e, dept d where e.deptno=d.deptno and hiredate<'31-Dec-82' and d.loc in('NEW YORK','CHICAGO')
62) Display employee name, job, deptname, and loc for all who are working as manager?
Select e.ename, e.job, d.dname, d.loc from emp e, dept d where e.deptno=d.deptno
and e.empno in (select mgr from emp where mgr is not null)
63) Display those employees whose manager name is Jones and also display their manager name?
Select e.ename sub, e1.ename from emp e, emp e1 where e.mgr=e1.empno and e1.ename='JONES'
64) Display name and salary of ford if his salary is equal to hisal of his grade?
Select ename, grade, hisal, sal from emp, salgrade where ename='FORD' and sal=hisal;
OR
Select grade, sal, hisal from emp, salgrade where ename='FORD' and sal between losal and hisal;
OR
Select ename, sal, hisal, grade from emp, salgrade where ename='FORD' and (grade, Sal) in (select grade, hisal from salgrade,emp where sal between losal and hisal);
65) Display employee name, job, deptname, his manager name, his grade and make an under department wise?
Select e.ename sub, e1.ename sup, e.job, d.dname, grade from emp e1, salgrade, dept d where e.mgr=e1.empno and e.sal between losal and hisal and e.deptno=d.deptno group by d.deptno, e.ename, e1.ename, e.job, d.dname, grade
OR
Select e.ename sub, e1.ename sup, e.job, d.dname, grade from emp e, e1, salgrade, dept d where e.mgr=e1.empno and e.sal between losal and hisal and e.deptno=d.deptno
66) List out all the employee names, job, salary, grade and deptname for every one in a company except ‘CLERK’. Sort on salary display the highest salary?
Select e.ename, e.job, e.sal, d.dname, grade from emp e, salgrade, dept d where (e.deptno=d.deptno and e.sal between losal and hisal) order by e.sal desc
67) Display employee name, job and his manager. Display also employees who are with out managers?
Select e.ename, e1.ename, e.job, e.sal, d.dname from emp e, emp e1, dept d where e.mgr=e1.empno (+) and e.deptno=d.deptno
68) Display Top 5 employee of a Company?
69) Display the names of those employees who are getting the highest salary?
Select ename, sal from emp where sal in (select max (sal) from emp)
70) Display those employees whose salary is equal to average of maximum and minimum?
Select * from emp where sal=(select (max (sal)+min (sal))/2 from emp)
71) Select count of employees in each department where count >3?
Select count (*) from emp group by deptno having count (*)>3
72) Display dname where atleast three are working and display only deptname?
select d.dname from dept d, emp e where e.deptno=d.deptno group by d.dname having count(*)>3
73) Display name of those managers name whose salary is more than average salary of Company?
Select distinct e1.ename, e1.sal from emp e, e1, dept d where e.deptno=d.deptno and e.mgr=e1.empno and e1.sal> (select avg (sal) from emp)
74) Display those managers name whose salary is more than average salary of his employees?
Select distinct e1.ename, e1.sal from emp e, e1, dept d where e.deptno=d.deptno and e.mgr=e1.empno and e1.sal>any (select avg (sal) from emp group by deptno)
75) Display employee name, sal, comm and net pay for those employees whose net pay is greater than or equal to any other employee salary of the company?
Select ename, sal, NVL (comm, 0), sal+NVL (comm, 0) from emp where sal+NVL (comm, 0) >any (select e.sal from emp e)
76) Display those employees whose salary is less than his manager but more than salary of other managers?
Select e.ename sub, e.sal from emp e, e1, dept d where e.deptno=d.deptno and e.mgr=e1.empno and e.salany (select e2.sal from emp e2, e, dept d1 where e.mgr=e2.empno and d1.deptno=e.deptno)
77) Display all employees’ names with total sal of company with each employee name?
78) Find the last 5(least) employees of company?
79) Find out the number of employees whose salary is greater than their managers salary?
Select e.ename, e.sal, e1.ename, e1.sal from emp e, e1, dept d where e.deptno=d.deptno and e.mgr=e1.empno and e.sal>e1.sal
80) Display the manager who are not working under president but they are working under any other manager?
Select e2.ename from emp e1, emp e2, emp e3 where e1.mgr=e2.empno and e2.mgr=e3.empno and e3.job! ='PRESIDENT';
81) Delete those department where no employee working?
Delete from emp where empno is null;
82) Delete those records from emp table whose deptno not available in dept table?
Delete from emp e where e.deptno not in (select deptno from dept)
83) Display those enames whose salary is out of grade available in salgrade table?
Select empno, sal from emp where sal<(select min (LOSAL) from salgrade) OR sal>(select max (hisal) from salgrade)
84) Display employee name, sal, comm and whose net pay is greater than any other in the company?
Select ename, sal, comm, sal+comm from emp where sal+comm>any (select sal+comm from emp)
85) Display name of those employees who are going to retire 31-Dec-99 if maximum job period is 30 years?
Select empno, hiredate, sysdate, to_char (sysdate,'yyyy') - to_char (hiredate,'yyyy') from emp where to_char (sysdate,'yyyy') - to_char (hiredate,'yyyy')=30
86) Display those employees whose salary is odd value?
Select ename, sal from emp where mod (sal, 2)! =0
87) Display those employees whose salary contains atleast 3 digits?
Select ename, sal from emp where length (sal)=3
88) Display those employees who joined in the company in the month of Dec?
Select empno, ename from emp where trim (to_char (hiredate,'Mon'))=trim ('DEC')
89) Display those employees whose name contains A?
Select ename from emp where ename like ('%A%')
90) Display those employees whose deptno is available in salary?
Select ename, sal from emp where deptno in (select distinct sal from emp);
91) Display those employees whose first 2 characters from hiredate - last 2 characters sal?
Select empno, hiredate, sal from emp where trim (substr (hiredate, 1,2))=trim (substr (sal, -2,2));
OR
Select hiredate, sal from emp where to_Char (hiredate,'dd')=trim (substr (sal, -2,2))
92) Display those employees whose 10% of salary is equal to the year joining?
Select ename, sal, 0.10*sal from emp where 0.10*sal=trim (to_char (hiredate,'yy'))
93) Display those employees who are working in sales or research?
Select e.ename from emp e, dept d where e.deptno=d.deptno and d.dname in ('SALES','RESEARCH');
94) Display the grade of Jones?
Select ename, grade from emp, salgrade where (grade, Sal) =(select grade, Sal from salgrade, emp where sal between losal and hisal and ename='JONES')
95) Display those employees who joined the company before 15th of the month?
select ename ,hiredate from emp where hiredate<'15-Jul-02' and hiredate >='01-jul-02';
96) Display those employees who has joined before 15th of the month?
select ename ,hiredate from emp where hiredate<'15-Jul-02'
97) Delete those records where no of employees in particular department is less than 3?
delete from emp where deptno in (select deptno from emp group by deptno having count(*) <3
98) Delete those employeewho joined the company 10 years back from today?
delete from emp where empno in (select empno from emp where to_char(sysdate,'yyyy')- to_char(hiredate,'yyyy')>=10)
99) Display the deptname the number of characters of which is equal to no of employee in any other department?
100) Display the deptname where no employee is working?
select deptno from emp where empno is null;
101) Display those employees who are working as manager?
select e2.ename from emp e1,e2 where e1.mgr=e2.empno and e2.empno is not null
102) Count th number of employees who are working as managers (Using set opetrator)?
select d.dname from dept d where length(d.dname) in (select count(*) from emp e where e.deptno!=d.deptno group by e.deptno)
103) Display the name of the dept those employees who joined the company on the same date?
select a.ename,b.ename from emp a,emp b where a.hiredate=b.hiredate and a.empno!=b.empno
104) Display those employees whose grade is equal to any number of sal but not equal to first number of sal?
select ename,sal,grade ,substr(sal,grade,1) from emp,salgrade where grade!= substr (sal,1,1) and grade = substr(sal,grade,1) and sal between losal and hisal
105) Count the no of employees working as manager using set operation?
Select count(empno) from emp where empno in (select a.empno from emp a intersect select b.mgr from emp b)
106) Display the name of employees who joined the company on the same date?
select a.ename,b.ename from emp a,emp b where a.hiredate=b.hiredate and a.empno!=b.empno;
107) Display the manager who is having maximum number of employees working under him?
select e2.ename,count(*) from emp e1,e2 where e1.mgr=e2.empno group by e2.ename Having count(*)=(select max(count(*)) from emp e1,e2 where e1.mgr=e2.empno group by e2.ename)
108) List out the employee name and salary increased by 15% and express as whole number of Dollars?
select ename,sal,lpad(translate(sal,sal,((sal +(sal*0.15))/50)),5,'$') from emp
147) Produce the output of the emptable "EMPLOYEE_AND JOB" for ename and job ?
Ans: select ename"EMPLOYEE_AND",job"JOB" FROM EMP;
148) List of employees with hiredate in the format of 'June 4 1988'?
Ans: select ename,to_char(hiredate,'Month dd yyyy') from emp;
149) print list of employees displaying 'Just salary' if more than 1500 if exactly 1500 display 'on taget' if less than 1500 display below 1500?
Ans: select ename,sal,
(
case when sal < 1500 then
'Below_Target'
when sal=1500 then
'On_Target'
when sal > 1500 then
'Above_Target'
else
'kkkkk'
end
)
from emp
150) Which query to calculate the length of time any employee has been with the company
Ans: select hiredate, to_char (hiredate,' HH:MI:SS') FROM emp
151) Given a string of the format 'nn/nn' . Verify that the first and last 2 characters are numbers. And that the middle character is '/' Print the expressions 'Yes' IF valid ‘NO’ of not valid. Use the following values to test your solution'12/54', 01/1a, '99/98'?
Ans:
152) Employes hire on OR Before 15th of any month are paid on the last friday of that month those hired after 15th are paid the last friday of th following month .print a list of employees .their hiredate and first pay date sort those who se salary contains first digit of their deptno?
Ans: select ename,hiredate, LAST_DAY ( next_day(hiredate,'Friday')),
(
case when to_char(hiredate,'dd') <=('15') then
LAST_DAY ( next_day(hiredate,'Friday'))
when to_char(hiredate,'dd')>('15') then
LAST_DAY( next_day(add_months(hiredate,1),'Friday'))
end
)
from emp
153) Display those managers who are getting less than his employees salary?
Ans: select a.empno, a.ename, a.sal, b.sal, b.empno, b.ename from emp a, emp b where a.mgr=b.empno and a.sal>b.sal
154) Print the details of employees who are subordinates to BLAKE?
Ans: select a.empno,a.ename ,b.ename from emp a, emp b where a.mgr=b.empno
and b.ename='BLAKE'
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