SQL Queries

--->1) Display the details of all employees

    SQL>Select * from emp;

--->2) Display the depart information from department table

    SQL>select * from dept;

--->3) Display the name and job for all the employees

    SQL>select ename,job from emp;

--->4) Display the name and salary  for all the employees

    SQL>select ename,sal from emp;

--->5) Display the employee no and total salary for all the employees

    SQL>select empno,ename,sal,comm, sal+nvl(comm,0) as"total  salary" from emp

--->6) Display the employee name and annual salary for all employees.

    SQL>select ename, 12*(sal+nvl(comm,0)) as "annual Sal" from emp

--->7) Display the names of all the employees who are working in depart number 10.

    SQL>select emame from emp where deptno=10;

--->8) Display the names of all the employees who are working as clerks and

   drawing a salary more than 3000.

   SQL>select ename from emp where job='CLERK' and sal>3000;

--->9) Display the employee number and name  who are earning comm.

   SQL>select empno,ename from emp where comm is not null;

--->10) Display the employee number and name  who do not earn any comm.

  SQL>select empno,ename from emp where comm is null;

--->11) Display the names of employees who are working as clerks,salesman or analyst and drawing a salary more than 3000.

  SQL>select ename  from emp where job='CLERK' OR JOB='SALESMAN' OR JOB='ANALYST' AND SAL>3000;

--->12) Display the names of the employees who are working in the company for the past 5 years;

  SQL>select ename  from emp where to_char(sysdate,'YYYY')-to_char(hiredate,'YYYY')>=5;

--->13) Display the list of employees who have joined the company before 30-JUN-90 or after 31-DEC-90.

  a)select ename from emp where hiredate < '30-JUN-1990' or hiredate > '31-DEC-90';

--->14) Display current Date.

  SQL>select sysdate from dual;

--->15) Display the list of all users in your database(use catalog table).

  SQL>select username from all_users;

--->16) Display the names of all tables from current user;

  SQL>select tname from tab;

--->17) Display the name of the current user.

  SQL>show user

--->18) Display the names of employees working in depart number 10 or 20 or 40 or employees working as CLERKS,SALESMAN or ANALYST.

  SQL>select ename from emp where deptno in(10,20,40) or job in('CLERKS','SALESMAN','ANALYST');

--->19) Display the names of employees whose name starts with alaphabet S.

  SQL>select ename from emp where ename like 'S%';

--->20) Display the Employee names for employees whose name ends with alaphabet S.

  SQL>select ename from emp where ename like '%S';

--->21) Display the names of employees whose names have second alphabet A in their names.

  SQL>select ename from emp where ename like '_A%';

--->22) select the names of the employee whose names is exactly five characters in length.

  SQL>select ename from emp where length(ename)=5;

--->23) Display the names of the employee who are not working as MANAGERS.

  SQL>select ename from emp where job not in('MANAGER');

--->24) Display the names of the employee who are not working as SALESMAN OR CLERK OR ANALYST.

  SQL>select ename from emp where job not in('SALESMAN','CLERK','ANALYST');

--->25) Display all rows from emp table.The system should wait after every screen full of informaction.

  SQL>set pause on

--->26) Display the total number of employee working in the company.

SQL>select count(*) from emp;

--->27) Display the total salary beiging paid to all employees.

SQL>select sum(sal) from emp;

--->28) Display the maximum salary from emp table.

SQL>select max(sal) from emp;

--->29) Display the minimum salary from emp table.

SQL>select min(sal) from emp;

--->30) Display the average salary from emp table.

SQL>select avg(sal) from emp;

--->31) Display the maximum salary being paid to CLERK.

SQL>select max(sal) from emp where job='CLERK';

--->32) Display the maximum salary being paid to depart number 20.

SQL>select max(sal) from emp where deptno=20;

--->33) Display the minimum salary being paid to any SALESMAN.

SQL>select min(sal) from emp where job='SALESMAN';

--->34) Display the average salary drawn by MANAGERS.

SQL>select avg(sal) from emp where job='MANAGER';

--->35) Display the total salary drawn by ANALYST working in depart number 40.

SQL>select sum(sal) from emp where job='ANALYST' and deptno=40;

--->36) Display the names of the employee in order of salary i.e the name of the employee earning lowest salary    should salary appear first.

SQL>select ename from emp order by sal;

--->37) Display the names of the employee in descending order of salary.

a)select ename from emp order by sal desc;

--->38) Display the names of the employee in order of employee name.

a)select ename from emp order by ename;

--->39) Display empno,ename,deptno,sal sort the output first base on name and within name by deptno and with in deptno by sal.

SQL>select empno,ename,deptno,sal from emp order by

--->40) Display the name of the employee along with their annual salary(sal*12).The name of the employee earning highest annual salary should apper first.

SQL>select ename,sal*12 from emp order by sal desc;

--->41) Display name,salary,hra,pf,da,total salary for each employee. The output 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.

SQL>select ename,sal,sal/100*15 as hra,sal/100*5 as pf,sal/100*10 as da, sal+sal/100*15+sal/100*10-sal/100*5 as total from emp;

--->42) Display depart numbers and total number of employees working in each department.

SQL>select deptno,count(deptno)from emp group by deptno;

--->43) Display the various jobs and total number of employees within each job group.

SQL>select job,count(job)from emp group by job;

--->44) Display the depart numbers and total salary for each department.

SQL>select deptno,sum(sal) from emp group by deptno;

--->45) Display the depart numbers and max salary for each department.

SQL>select deptno,max(sal) from emp group by deptno;

--->46) Display the various jobs and total salary for each job

SQL>select job,sum(sal) from emp group by job;

--->47) Display the various jobs and total salary for each job

SQL>select job,min(sal) from emp group by job;

--->48) Display the depart numbers with more than three employees in each dept.

SQL>select deptno,count(deptno) from emp group by deptno having count(*)>3;

--->49) Display the various jobs along with total salary for each of the jobs where total salary is greater than 40000.

SQL>select job,sum(sal) from emp group by job having sum(sal)>40000;

--->50) 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.

SQL>select job,count(empno) from emp group by job having count(job)>3

--->51) Display the name of the empployee who earns highest salary.

SQL>select ename from emp where sal=(select max(sal) from emp);

--->52) Display the employee number and name for employee working as clerk and earning highest salary among clerks.

SQL>select empno,ename from emp where where job='CLERK' and sal=(select max(sal) from emp  where job='CLERK');

--->53) Display the names of salesman who earns a salary more than the highest salary of any clerk.

SQL>select ename,sal from emp where job='SALESMAN' and sal>(select max(sal) from emp where job='CLERK');

--->54) Display the names of clerks who earn a salary more than the lowest salary of any salesman.

SQL>select ename from emp where job='CLERK' and sal>(select min(sal) from emp where job='SALESMAN');

--->Display the names of employees who earn a salary more than that of Jones or that of salary grether than   that of scott.

SQL>select ename,sal from emp where sal> (select sal from emp where ename='JONES')and sal> (select sal from emp where ename='SCOTT');

--->55) Display the names of the employees who earn highest salary in their respective departments.

SQL>select ename,sal,deptno from emp where sal in(select max(sal) from emp group by deptno);

--->56) Display the names of the employees who earn highest salaries in their respective job groups.

SQL>select ename,sal,job from emp where sal in(select max(sal) from emp group by job)

--->57) Display the employee names who are working in accounting department.

SQL>select ename from emp where deptno=(select deptno from dept where dname='ACCOUNTING')

--->58) Display the employee names who are working in Chicago.

SQL>select ename from emp where deptno=(select deptno from dept where LOC='CHICAGO')

--->59) Display the Job groups having total salary greater than the maximum salary for managers.

SQL>SELECT JOB,SUM(SAL) FROM EMP GROUP BY JOB HAVING SUM(SAL)>(SELECT MAX(SAL) FROM EMP WHERE JOB='MANAGER');

--->60) Display the names of employees from department number 10 with salary grether than that of any employee working in other department.

SQL>select ename from emp where deptno=10 and sal>any(select sal from emp where deptno not in 10).

--->61) Display the names of the employees from department number 10 with salary greater than that of all employee working in other departments.

SQL>select ename from emp where deptno=10 and sal>all(select sal from emp where deptno not in 10).

--->62) Display the names of the employees in Uppercase.

SQL>select upper(ename)from emp

--->63) Display the names of the employees in Lowecase.

SQL>select lower(ename)from emp

--->64) Display the names of the employees in Propercase.

SQL>select initcap(ename)from emp;

--->65) Display the length of Your name using appropriate function.

SQL>select length('name') from dual

--->66) Display the length of all the employee names.

SQL>select length(ename) from emp;

--->67) select name of the employee concatenate with employee number.

SQL>select ename||empno from emp;

--->68) User appropriate function and extract 3 characters starting from 2 characters from the following  string 'Oracle'. i.e the out put should be 'ac'.

SQL>select substr('oracle',3,2) from dual

--->69) Find the First occurance of character 'a' from the following string i.e 'Computer Maintenance Corporation'.

SQL>SELECT INSTR('Computer Maintenance Corporation','a',1) FROM DUAL

--->70) Replace every occurance of alphabhet A with B in the string Allens(use translate function)

SQL>select translate('Allens','A','B') from dual

--->71) Display the informaction from emp table.Where job manager is found it should be displayed as boos(Use replace function).

SQL>select replace(JOB,'MANAGER','BOSS') FROM EMP;

--->72) Display empno,ename,deptno from emp table.Instead of display department numbers display the related department name(Use decode function).

SQL>select empno,ename,decode(deptno,10,'ACCOUNTING',20,'RESEARCH',30,'SALES',40,'OPRATIONS') from emp;

--->73) Display your age in days.

SQL>select to_date(sysdate)-to_date('10-sep-77')from dual

--->74) Display your age in months.

SQL>select months_between(sysdate,'10-sep-77') from dual

--->75) Display the current date as 15th Augest Friday Nineteen Ninety Saven.

SQL>select to_char(sysdate,'ddth Month day year') from dual

--->76) Display the following output for each row from emp table.scott has joined the company on wednesday 13th August ninten nintey.

SQL>select ENAME||' HAS JOINED THE COMPANY ON  '||to_char(HIREDATE,'day ddth Month  year')   from EMP;

--->77) Find the date for nearest saturday after current date.

SQL>SELECT NEXT_DAY(SYSDATE,'SATURDAY')FROM DUAL;

--->78) Display current time.

SQL>select to_char(sysdate,'hh:MM:ss') from dual.

--->79) Display the date three months Before the current date.

SQL>select add_months(sysdate,3) from dual;

--->80) Display the common jobs from department number 10 and 20.

SQL>select job from emp where deptno=10 and job in(select job from emp where deptno=20);

--->81) Display the jobs found in department 10 and 20 Eliminate duplicate jobs.

SQL>select distinct(job) from emp where deptno=10 or deptno=20

--->           (or)

SQL>select distinct(job) from emp where deptno in(10,20);

--->82) Display the jobs which are unique to department 10.

SQL>select distinct(job) from emp where deptno=10

--->83) Display the details of those who do not have any person working under them.

SQL>select e.ename from emp,emp e where emp.mgr=e.empno group by e.ename having count(*)=1;

--->84) Display the details of those employees who are in sales department and grade is 3.

SQL>select * from emp where deptno=(select deptno from dept where dname='SALES')and sal between(select losal from salgrade where grade=3)and   (select hisal from salgrade where grade=3);

--->85) Display those who are not managers and who are managers any one.

--->i)display the managers names

SQL>select distinct(m.ename) from emp e,emp m where m.empno=e.mgr;

--->ii)display the who are not managers

SQL>select ename from emp where ename not in(select distinct(m.ename) from emp e,emp m where m.empno=e.mgr);

--->86) Display those employee whose name contains not less than 4 characters.

SQL>select ename from emp where length(ename)>4;

--->87) Display those department whose name start with "S" while the location name ends with "K".

SQL>select dname from dept where dname like 'S%' and loc like '%K';

--->88) Display those employees whose manager name is JONES.

SQL>select p.ename from emp e,emp p where e.empno=p.mgr and e.ename='JONES';

--->89) Display those employees whose salary is more than 3000 after giving 20% increment.

SQL>select ename,sal from emp where (sal+sal*.2)>3000;

--->90) Display all employees while their dept names;

SQL>select ename,dname from emp,dept where emp.deptno=dept.deptno

--->91) Display ename who are working in sales dept.

SQL>select ename from emp where deptno=(select deptno from dept where dname='SALES');

--->92) Display employee name,deptname,salary and comm for those sal in between 2000 to 5000 while location is chicago.

SQL>select ename,dname,sal,comm from emp,dept where sal  between 2000 and 5000 and loc='CHICAGO' and emp.deptno=dept.deptno;

--->93)Display those employees whose salary greter than his manager salary.

SQL>select p.ename from emp e,emp p where e.empno=p.mgr and p.sal>e.sal

--->94) Display those employees who are working in the same dept where his manager is work.

SQL>select p.ename from emp e,emp p where e.empno=p.mgr and p.deptno=e.deptno;

--->95) Display those employees who are not working under any manager.

SQL>select ename from emp where mgr is null

--->96) Display grade and employees name for the dept no 10 or 30 but grade is not 4 while joined the company before 31-dec-82.

SQL>select ename,grade from emp,salgrade where sal between losal and hisal and deptno     in(10,30) and grade<>4 and hiredate<'31-DEC-82';

--->97) Update the salary of each employee by 10% increment who are not eligiblw for commission.

SQL>update emp set sal=sal+sal*10/100 where comm is null;

--->98) SELECT those employee who joined the company before 31-dec-82 while their dept location is newyork or  Chicago.

SQL>SELECT EMPNO,ENAME,HIREDATE,DNAME,LOC FROM EMP,DEPT WHERE (EMP.DEPTNO=DEPT.DEPTNO)AND HIREDATE <'31-DEC-82' AND DEPT.LOC IN('CHICAGO','NEW YORK');

--->99) DISPLAY EMPLOYEE NAME,JOB,DEPARTMENT,LOCATION FOR ALL WHO ARE WORKING AS  MANAGER?

SQL>select ename,JOB,DNAME,LOCATION from emp,DEPT where mgr is not null;

100) DISPLAY THOSE EMPLOYEES WHOSE MANAGER NAME IS JONES? ---> [AND ALSO DISPLAY THEIR MANAGER NAME]?

SQL> SELECT P.ENAME FROM EMP E, EMP P WHERE E.EMPNO=P.MGR AND E.ENAME='JONES';

--->101) Display name and salary of ford if his salary is equal to hisal of his grade

SQL>select ename,sal,grade from emp,salgrade where sal between losal and hisal and ename ='FORD' AND HISAL=SAL;

--->102) Display employee name,job,depart name ,manager name,his grade and make out an under department wise?

SQL>SELECT E.ENAME,E.JOB,DNAME,EMP.ENAME,GRADE FROM EMP,EMP E,SALGRADE,DEPT

WHERE EMP.SAL BETWEEN LOSAL AND HISAL AND EMP.EMPNO=E.MGR AND EMP.DEPTNO=DEPT.DEPTNO ORDER BY DNAME

--->103) List out all employees name,job,salary,grade and depart name for every one in the company  except 'CLERK'.Sort on salary display the highest salary?

SQL>SELECT ENAME,JOB,DNAME,SAL,GRADE FROM EMP,SALGRADE,DEPT WHERE SAL BETWEEN LOSAL AND HISAL AND EMP.DEPTNO=DEPT.DEPTNO AND JOB NOT IN('CLERK')ORDER BY SAL ASC;

--->104) Display the employee name,job and his manager.Display also employee who are without manager?

SQL>select e.ename,e.job,eMP.ename AS Manager from emp,emp e where emp.empno(+)=e.mgr

--->105) Find out the top 5 earners of company?

SQL>SELECT DISTINCT SAL FROM EMP E WHERE 5>=(SELECT COUNT(DISTINCT SAL) FROM EMP A WHERE A.SAL>=E.SAL)ORDER BY SAL DESC;

--->106) Display name of those employee who are getting the highest salary?

SQL>select ename from emp where sal=(select max(sal) from emp);

--->107) Display those employee whose salary is equal to average of maximum and minimum?

SQL>select ename from emp where sal=(select max(sal)+min(sal)/2 from emp);

--->108) Select count of employee in each department  where count greater than 3?

SQL>select count(*) from emp group by deptno having count(deptno)>3

--->109) Display dname where at least 3 are working and display only department name?

SQL>select distinct d.dname from dept d,emp e where d.deptno=e.deptno and 3>any (select count(deptno) from emp group by deptno)

--->110) Display name of those managers name whose salary is more than average salary of his company?

SQL>SELECT E.ENAME,EMP.ENAME FROM EMP,EMP E WHERE EMP.EMPNO=E.MGR AND E.SAL>(SELECT AVG(SAL) FROM EMP);

--->111)Display those managers name whose salary is more than average salary of his employee?

SQL>SELECT DISTINCT EMP.ENAME FROM EMP,EMP E WHERE E.SAL <(SELECT AVG(EMP.SAL) FROM EMP WHERE EMP.EMPNO=E.MGR GROUP BY EMP.ENAME) AND EMP.EMPNO=E.MGR;

--->112) Display employee name,sal,comm and net pay for those employee whose net pay is greter than or equal to any other employee salary of the company?

SQL>select ename,sal,comm,sal+nvl(comm,0) as NetPay from emp where sal+nvl(comm,0) >any (select sal from emp)

--->113) Display all employees names with total sal of company with each employee name?

SQL>SELECT ENAME,(SELECT SUM(SAL)  FROM EMP) FROM EMP;

--->114) Find out last 5(least)earners of the company.?

SQL>SELECT DISTINCT SAL FROM EMP E WHERE   5>=(SELECT COUNT(DISTINCT SAL) FROM EMP A WHERE A.SAL<=E.SAL) ORDER BY SAL DESC;

--->115) Find out the number of employees whose salary is greater than their manager salary?

SQL>SELECT E.ENAME FROM EMP ,EMP E WHERE EMP.EMPNO=E.MGR AND EMP.SAL<E.SAL;

--->116) Display those department where no employee working?

SQL>select dname from emp,dept where emp.deptno not in(emp.deptno)

--->117) Display those employee whose salary is ODD value?

SQL>select * from emp where sal<0;

--->118) Display those employee whose salary contains alleast 3 digits?

SQL>select * from emp where length(sal)>=3;

--->119) Display those employee who joined in the company in the month of Dec?

SQL>select ename from emp where to_char(hiredate,'MON')='DEC';

--->120) Display those employees whose name contains "A"?

SQL>select ename from emp where instr(ename,'A')>0;

--->      or

SQL>select ename from emp where ename like('%A%');

--->121) Display those employee whose deptno is available in salary?

SQL>select emp.ename from emp, emp e where emp.sal=e.deptno;

--->122) Display those employee whose first 2 characters from hiredate -last 2 characters of salary?

SQL>select ename,SUBSTR(hiredate,1,2)||ENAME||substr(sal,-2,2) from emp

--->123) Display those employee whose 10% of salary is equal to the year of joining?

SQL>select ename from emp where to_char(hiredate,'YY')=sal*0.1;

--->124) Display those employee who are working in sales or research?

SQL>SELECT ENAME FROM EMP WHERE DEPTNO IN(SELECT DEPTNO FROM DEPT WHERE DNAME IN('SALES','RESEARCH'));

--->125) Display the grade of jones?

SQL>SELECT ENAME,GRADE FROM EMP,SALGRADE WHERE SAL BETWEEN LOSAL AND HISAL AND Ename='JONES';

--->126) Display those employees who joined the company before 15 of the month?

a)select ename from emp where to_char(hiredate,'DD')<15;

--->127) Display those employee who has joined before 15th of the month.

a)select ename from emp where to_char(hiredate,'DD')<15;

--->128) Delete those records where no of employees in a particular department is less than 3.

SQL>delete from emp where deptno=(select deptno from emp group by deptno having count(deptno)<3);

--->129) Display the name of the department where no employee working.

SQL> SELECT E.ENAME,E.JOB,M.ENAME,M.JOB FROM EMP E,EMP M WHERE E.MGR=M.EMPNO

--->130) Display those employees who are working as manager.

SQL>SELECT M.ENAME MANAGER FROM EMP M ,EMP E WHERE E.MGR=M.EMPNO GROUP BY M.ENAME

--->131) Display those employees whose grade is equal to any number of sal but not equal to first number of sal?

SQL> SELECT ENAME,GRADE FROM EMP,SALGRADE  WHERE GRADE NOT IN(SELECT SUBSTR(SAL,0,1)FROM EMP)

--->132) Print the details of all the employees who are Sub-ordinate to BLAKE?

SQL>select emp.ename from emp, emp e where emp.mgr=e.empno and e.ename='BLAKE';

--->133) Display employee name and his salary whose salary is greater than highest average of department number?

SQL>SELECT SAL FROM EMP WHERE SAL>(SELECT MAX(AVG(SAL)) FROM EMP  GROUP BY DEPTNO);

--->134) Display the 10th record of emp table(without using rowid)

SQL>SELECT * FROM EMP WHERE ROWNUM<11 MINUS SELECT * FROM EMP WHERE ROWNUM<10

--->135) Display the half of the ename's in upper case and remaining lowercase?

SQL>SELECT SUBSTR(LOWER(ENAME),1,3)||SUBSTR(UPPER(ENAME),3,LENGTH(ENAME)) FROM EMP;

--->136) Display the 10th record of emp table without using group by and rowid?

SQL>SELECT * FROM EMP WHERE ROWNUM<11 MINUS SELECT * FROM EMP WHERE ROWNUM<10

--->  Delete the 10th record of emp table.

SQL>DELETE FROM EMP WHERE EMPNO=(SELECT EMPNO FROM EMP WHERE ROWNUM<11   MINUS SELECT EMPNO FROM EMP WHERE ROWNUM<10)

--->137) Create a copy of emp table;

SQL>create table new_table as select * from emp where 1=2;

 

--->138) Select ename if ename exists more than once.

SQL>select ename  from emp e group by ename having count(*)>1;

--->139) Display all enames in reverse order?(SMITH:HTIMS).

SQL>SELECT REVERSE(ENAME)FROM EMP;

--->140) Display those employee whose joining of month and grade is equal.

SQL>SELECT ENAME FROM EMP WHERE SAL BETWEEN (SELECT LOSAL FROM SALGRADE WHERE GRADE=TO_CHAR(HIREDATE,'MM')) AND (SELECT HISAL FROM SALGRADE WHERE GRADE=TO_CHAR(HIREDATE,'MM'));

  

--->141) Display those employee whose joining DATE is available in deptno.

SQL>SELECT ENAME FROM EMP WHERE TO_CHAR(HIREDATE,'DD')=DEPTNO

--->142) Display those employees name as follows ---> A ALLEN ---> B BLAKE

SQL> SELECT SUBSTR(ENAME,1,1),ENAME FROM EMP;

--->143) List out the employees ename,sal,PF(20% OF SAL) from emp;

SQL>SELECT ENAME,SAL,SAL*.2 AS PF FROM EMP; 

--->144) Create table emp with only one column empno;

SQL>Create table emp as select empno from emp where 1=2;

--->145) Add this column to emp table ename vrachar2(20).

SQL>alter table emp add(ename varchar2(20));

--->146) Oops I forgot give the primary key constraint.  Add in now.

SQL>alter table emp add primary key(empno);

--->147) Now increase the length of ename column to 30 characters.

SQL>alter table emp modify(ename varchar2(30));

--->148) Add salary column to emp table.

SQL>alter table emp add(sal number(10));

--->149) I want to give a validation saying that salary cannot be greater 10,000(note give a name to this constraint)

SQL>alter table emp add constraint chk_001 check(sal<=10000)

--->150) For the time being I have decided that I will not impose this validation.My boss has agreed to pay more than 10,000.

SQL>again alter the table or drop constraint with  alter table emp drop constraint chk_001 (or)Disable the constraint by using  alter table emp modify constraint chk_001 disable;

--->151) My boss has changed his mind.  Now he doesn't want to pay more than 10,000.so revoke that salary constraint.

SQL>alter table emp modify constraint chk_001 enable;

--->152) Add column called as mgr to your emp table;

SQL>alter table emp add(mgr number(5));

--->153) Oh! This column should be related to empno.  Give a command to add this constraint.

SQL>ALTER TABLE EMP ADD CONSTRAINT MGR_DEPT FOREIGN KEY(MGR) REFERENCES EMP(EMPNO)

                     

--->154) Add deptno column to your emp table;

SQL>alter table emp add(deptno number(5));  

--->155) This deptno column should be related to deptno column of dept table;

SQL>alter table emp add constraint dept_001 foreign key(deptno) reference dept(deptno)  [deptno should be primary key]

--->156) Give the command to add the constraint.

SQL>alter table <table_name) add constraint <constraint_name> <constraint type>

--->157) Create table called as newemp.  Using single command create this table as well as get data into this table(use create table as);

SQL>create table newemp as select * from emp;

--->SQL>Create table called as newemp.  This table should contain only empno,ename,dname.

SQL>create table newemp as select empno,ename,dname from emp,dept where 1=2;

--->158) Delete the rows of employees who are working in the company for more than 2 years.

SQL>delete from emp where (sysdate-hiredate)/365>2;

--->159) Provide a commission(10% Comm Of Sal) to employees who are not earning any commission.

SQL>select sal*0.1 from emp where comm is null

--->160) If any employee has commission his commission should be incremented by 10% of his salary.

SQL>update emp set comm=sal*.1 where comm is not null;

--->161) Display employee name and department name for each employee.

SQL>select empno,dname from emp,dept where emp.deptno=dept.deptno

--->162)Display employee number,name and location of the department in which he is working.

SQL>select empno,ename,loc,dname from emp,dept where emp.deptno=dept.deptno;

--->163) Display ename,dname even if there are no employees working in a particular department(use outer join).

SQL>select ename,dname from emp,dept where emp.deptno=dept.deptno(+)

--->164) Display employee name and his manager name.

SQL>select p.ename,e.ename from emp e,emp p where e.empno=p.mgr;

--->165) Display the department name and total number of employees in each department.

SQL>select dname,count(ename) from emp,dept where emp.deptno=dept.deptno group by dname;

--->166)Display the department name along with total salary in each department.

SQL>select dname,sum(sal) from emp,dept where emp.deptno=dept.deptno group by dname;

--->167) Display itemname and total sales amount for each item.

SQL>select itemname,sum(amount) from item group by itemname;

--->168) Write a Query To Delete The Repeted Rows from emp table;

SQL>Delete from emp where rowid not in(select min(rowid)from emp group by ename)

  

--->169) TO DISPLAY 5 TO 7 ROWS FROM A TABLE

SQL>select ename from emp where rowid in(select rowid from emp where rownum<=7  minus select rowid from empi where rownum<5)

--->170)  DISPLAY  TOP N ROWS FROM TABLE?

SQL>SELECT * FROM (SELECT *  FROM EMP ORDER BY ENAME DESC) WHERE ROWNUM <10;

--->171) DISPLAY   TOP 3 SALARIES FROM EMP;

SQL>SELECT SAL FROM ( SELECT  * FROM EMP ORDER  BY SAL DESC ) WHERE ROWNUM <4

--->172) DISPLAY  9th FROM THE EMP TABLE?

SQL>SELECT ENAME FROM EMP

   WHERE ROWID=(SELECT ROWID FROM EMP WHERE ROWNUM<=10

   MINUS

   SELECT ROWID FROM EMP WHERE ROWNUM <10)

   select second max salary from emp;

   select max(sal) fromemp where sal<(select  max(sal) from emp);