To fetch ALTERNATE records from a
table. (EVEN NUMBERED)
select * from emp where rowid in (select decode(mod(rownum,2),0,rowid, null) from emp);
To select ALTERNATE records from a table. (ODD NUMBERED)
select * from emp where rowid in (select decode(mod(rownum,2),0,null ,rowid) from emp);
Find the 3rd MAX salary in the emp table.
select distinct sal from emp e1 where 3 = (select count(distinct sal) from emp e2 where e1.sal <= e2.sal);
Find the 3rd MIN salary in the emp table.
select distinct sal from emp e1 where 3 = (select count(distinct sal) from emp e2where e1.sal >= e2.sal);
Select FIRST n records from a table.
select * from emp where rownum <= &n;
Select LAST n records from a table
select * from emp minus select * from emp where rownum <= (select count(*) - &n from emp);
List dept no., Dept name for all the departments in which there are no employees in the department.
select * from dept where deptno not in (select deptno from emp);
alternate solution: select * from dept a where not exists (select * from emp b where a.deptno = b.deptno);
alternate solution: select empno,ename,b.deptno,dname from emp a, dept b where a.deptno(+) = b.deptno and empno is null;
How to get 3 Max salaries ?
select distinct sal from emp a where 3 >= (select count(distinct sal) from emp b where a.sal <= b.sal) order by a.sal desc;
How to get 3 Min salaries ?
select distinct sal from emp a where 3 >= (select count(distinct sal) from emp b where a.sal >= b.sal);
How to get nth max salaries ?
select distinct hiredate from emp a where &n = (select count(distinct sal) from emp b where a.sal >= b.sal);
Select DISTINCT RECORDS from emp table.
select * from emp a where rowid = (select max(rowid) from emp b where a.empno=b.empno);
How to delete duplicate rows in a table?
delete from emp a where rowid != (select max(rowid) from emp b where a.empno=b.empno);
Count of number of employees in department wise.
select count(EMPNO), b.deptno, dname from emp a, dept b where a.deptno(+)=b.deptno group by b.deptno,dname;
Suppose there is annual salary information provided by emp table. How to fetch monthly salary of each and every employee?
select ename,sal/12 as monthlysal from emp;
Select all record from emp table where deptno =10 or 40.
select * from emp where deptno=40 or deptno=10;
Select all record from emp table where deptno=30 and sal>1500.
select * from emp where deptno=30 and sal>1500;
Select all record from emp where job not in SALESMAN or CLERK.
select * from emp where job not in ('SALESMAN','CLERK');
Select all record from emp where ename in 'BLAKE','SCOTT','KING' and 'FORD'.
select * from emp where ename in('JONES','BLAKE','SCOTT','KING','FORD');
Select all records where ename starts with ‘S’ and its lenth is 6 char.
select * from emp where ename like'S____';
Select all records where ename may be any no of character but it should end with ‘R’.
select * from emp where ename like'%R';
Count MGR and their salary in emp table.
select count(MGR),count(sal) from emp;
In emp table add comm+sal as total sal .
select ename,(sal+nvl(comm,0)) as totalsal from emp;
Select any salary <3000 from emp table.
select * from emp where sal> any(select sal from emp where sal<3000);
Select all salary <3000 from emp table.
select * from emp where sal> all(select sal from emp where sal<3000);
Select all the employee group by deptno and sal in descending order.
select ename,deptno,sal from emp order by deptno,sal desc;
How can I create an empty table emp1 with same structure as emp?
Create table emp1 as select * from emp where 1=2;
How to retrive record where sal between 1000 to 2000?
Select * from emp where sal>=1000 And sal<2000
Select all records where dept no of both emp and dept table matches.
select * from emp where exists(select * from dept where emp.deptno=dept.deptno)
If there are two tables emp1 and emp2, and both have common record. How can I fetch all the recods but common records only once?
(Select * from emp) Union (Select * from emp1)
How to fetch only common records from two tables emp and emp1?
(Select * from emp) Intersect (Select * from emp1)
How can I retrive all records of emp1 those should not present in emp2?
(Select * from emp) Minus (Select * from emp1)
Count the totalsal deptno wise where more than 2 employees exist.
SELECT deptno, sum(sal) As totalsal
FROM emp
GROUP BY deptno
HAVING COUNT(empno) > 2
To see current user name
Sql> show user;
Change SQL prompt name
SQL> set sqlprompt “Manimara > “
Switch to DOS prompt
SQL> host
How do I eliminate the duplicate rows ?
SQL> delete from table_name where rowid not in (select max(rowid) from table group by duplicate_values_field_name);
or
SQL> delete duplicate_values_field_name dv from table_name ta where rowid <(select min(rowid) from table_name tb where ta.dv=tb.dv);
Example.
Table Emp
Empno Ename
101 Scott
102 Jiyo
103 Millor
104 Jiyo
105 Smith
delete ename from emp a where rowid < ( select min(rowid) from emp b where a.ename = b.ename);
The output like,
Empno Ename
101 Scott
102 Millor
103 Jiyo
104 Smith
How do I display row number with records?
To achive this use rownum pseudocolumn with query, like SQL> SQL> select rownum, ename from emp;
Output:
1 Scott
2 Millor
3 Jiyo
4 Smith
Display the records between two range
select rownum, empno, ename from emp where rowid in (select rowid from emp where rownum <=&upto minus select rowid from emp where rownum<&Start);
Enter value for upto: 10
Enter value for Start: 7
ROWNUM EMPNO ENAME
--------- --------- ----------
1 7782 CLARK
2 7788 SCOTT
3 7839 KING
4 7844 TURNER
I know the nvl function only allows the same data type(ie. number or char or date
Nvl(comm, 0)), if commission is null then the text “Not Applicable” want to display, instead of
blank space. How do I write the query?
SQL> select nvl(to_char(comm.),'NA') from emp;
Output :
NVL(TO_CHAR(COMM),'NA')
-----------------------
NA
300
500
NA
1400
NA
NA
Oracle cursor : Implicit & Explicit cursors
Oracle uses work areas called private SQL areas to create SQL statements.
PL/SQL construct to identify each and every work are used, is called as Cursor.
For SQL queries returning a single row, PL/SQL declares all implicit cursors.
For queries that returning more than one row, the cursor needs to be explicitly declared.
Explicit Cursor attributes
There are four cursor attributes used in Oracle
cursor_name%Found, cursor_name%NOTFOUND, cursor_name%ROWCOUNT, cursor_name%ISOPEN
Implicit Cursor attributes
Same as explicit cursor but prefixed by the word SQL
SQL%Found, SQL%NOTFOUND, SQL%ROWCOUNT, SQL%ISOPEN
Tips : 1. Here SQL%ISOPEN is false, because oracle automatically closed the implicit cursor after
executing SQL statements.
: 2. All are Boolean attributes.
Find out nth highest salary from emp table
SELECT DISTINCT (a.sal) FROM EMP A WHERE &N = (SELECT COUNT (DISTINCT (b.sal)) FROM EMP B
WHERE a.sal<=b.sal);
Enter value for n: 2
SAL
---------
3700
To view installed Oracle version information
SQL> select banner from v$version;
Display the number value in Words
SQL> select sal, (to_char(to_date(sal,'j'), 'jsp'))
from emp;
the output like,
SAL (TO_CHAR(TO_DATE(SAL,'J'),'JSP'))
--------- -----------------------------------------------------
800 eight hundred
1600 one thousand six hundred
1250 one thousand two hundred fifty
If you want to add some text like,
Rs. Three Thousand only.
SQL> select sal "Salary ",
(' Rs. '|| (to_char(to_date(sal,'j'), 'Jsp'))|| ' only.'))
"Sal in Words" from emp
/
Salary Sal in Words
------- ------------------------------------------------------
800 Rs. Eight Hundred only.
1600 Rs. One Thousand Six Hundred only.
1250 Rs. One Thousand Two Hundred Fifty only.
Display Odd/ Even number of records
Odd number of records:
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);
1
3
5
Even number of records:
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)
2
4
6
Which date function returns number value?
months_between
Any three PL/SQL Exceptions?
Too_many_rows, No_Data_Found, Value_Error, Zero_Error, Others
What are PL/SQL Cursor Exceptions?
Cursor_Already_Open, Invalid_Cursor
Other way to replace query result null value with a text
SQL> Set NULL ‘N/A’
to reset SQL> Set NULL ‘’
What are the more common pseudo-columns?
SYSDATE, USER , UID, CURVAL, NEXTVAL, ROWID, ROWNUM
What is the output of SIGN function?
1 for positive value,
0 for Zero,
-1 for Negative value.
select * from emp where rowid in (select decode(mod(rownum,2),0,rowid, null) from emp);
To select ALTERNATE records from a table. (ODD NUMBERED)
select * from emp where rowid in (select decode(mod(rownum,2),0,null ,rowid) from emp);
Find the 3rd MAX salary in the emp table.
select distinct sal from emp e1 where 3 = (select count(distinct sal) from emp e2 where e1.sal <= e2.sal);
Find the 3rd MIN salary in the emp table.
select distinct sal from emp e1 where 3 = (select count(distinct sal) from emp e2where e1.sal >= e2.sal);
Select FIRST n records from a table.
select * from emp where rownum <= &n;
Select LAST n records from a table
select * from emp minus select * from emp where rownum <= (select count(*) - &n from emp);
List dept no., Dept name for all the departments in which there are no employees in the department.
select * from dept where deptno not in (select deptno from emp);
alternate solution: select * from dept a where not exists (select * from emp b where a.deptno = b.deptno);
alternate solution: select empno,ename,b.deptno,dname from emp a, dept b where a.deptno(+) = b.deptno and empno is null;
How to get 3 Max salaries ?
select distinct sal from emp a where 3 >= (select count(distinct sal) from emp b where a.sal <= b.sal) order by a.sal desc;
How to get 3 Min salaries ?
select distinct sal from emp a where 3 >= (select count(distinct sal) from emp b where a.sal >= b.sal);
How to get nth max salaries ?
select distinct hiredate from emp a where &n = (select count(distinct sal) from emp b where a.sal >= b.sal);
Select DISTINCT RECORDS from emp table.
select * from emp a where rowid = (select max(rowid) from emp b where a.empno=b.empno);
How to delete duplicate rows in a table?
delete from emp a where rowid != (select max(rowid) from emp b where a.empno=b.empno);
Count of number of employees in department wise.
select count(EMPNO), b.deptno, dname from emp a, dept b where a.deptno(+)=b.deptno group by b.deptno,dname;
Suppose there is annual salary information provided by emp table. How to fetch monthly salary of each and every employee?
select ename,sal/12 as monthlysal from emp;
Select all record from emp table where deptno =10 or 40.
select * from emp where deptno=40 or deptno=10;
Select all record from emp table where deptno=30 and sal>1500.
select * from emp where deptno=30 and sal>1500;
Select all record from emp where job not in SALESMAN or CLERK.
select * from emp where job not in ('SALESMAN','CLERK');
Select all record from emp where ename in 'BLAKE','SCOTT','KING' and 'FORD'.
select * from emp where ename in('JONES','BLAKE','SCOTT','KING','FORD');
Select all records where ename starts with ‘S’ and its lenth is 6 char.
select * from emp where ename like'S____';
Select all records where ename may be any no of character but it should end with ‘R’.
select * from emp where ename like'%R';
Count MGR and their salary in emp table.
select count(MGR),count(sal) from emp;
In emp table add comm+sal as total sal .
select ename,(sal+nvl(comm,0)) as totalsal from emp;
Select any salary <3000 from emp table.
select * from emp where sal> any(select sal from emp where sal<3000);
Select all salary <3000 from emp table.
select * from emp where sal> all(select sal from emp where sal<3000);
Select all the employee group by deptno and sal in descending order.
select ename,deptno,sal from emp order by deptno,sal desc;
How can I create an empty table emp1 with same structure as emp?
Create table emp1 as select * from emp where 1=2;
How to retrive record where sal between 1000 to 2000?
Select * from emp where sal>=1000 And sal<2000
Select all records where dept no of both emp and dept table matches.
select * from emp where exists(select * from dept where emp.deptno=dept.deptno)
If there are two tables emp1 and emp2, and both have common record. How can I fetch all the recods but common records only once?
(Select * from emp) Union (Select * from emp1)
How to fetch only common records from two tables emp and emp1?
(Select * from emp) Intersect (Select * from emp1)
How can I retrive all records of emp1 those should not present in emp2?
(Select * from emp) Minus (Select * from emp1)
Count the totalsal deptno wise where more than 2 employees exist.
SELECT deptno, sum(sal) As totalsal
FROM emp
GROUP BY deptno
HAVING COUNT(empno) > 2
To see current user name
Sql> show user;
Change SQL prompt name
SQL> set sqlprompt “Manimara > “
Switch to DOS prompt
SQL> host
How do I eliminate the duplicate rows ?
SQL> delete from table_name where rowid not in (select max(rowid) from table group by duplicate_values_field_name);
or
SQL> delete duplicate_values_field_name dv from table_name ta where rowid <(select min(rowid) from table_name tb where ta.dv=tb.dv);
Example.
Table Emp
Empno Ename
101 Scott
102 Jiyo
103 Millor
104 Jiyo
105 Smith
delete ename from emp a where rowid < ( select min(rowid) from emp b where a.ename = b.ename);
The output like,
Empno Ename
101 Scott
102 Millor
103 Jiyo
104 Smith
How do I display row number with records?
To achive this use rownum pseudocolumn with query, like SQL> SQL> select rownum, ename from emp;
Output:
1 Scott
2 Millor
3 Jiyo
4 Smith
Display the records between two range
select rownum, empno, ename from emp where rowid in (select rowid from emp where rownum <=&upto minus select rowid from emp where rownum<&Start);
Enter value for upto: 10
Enter value for Start: 7
ROWNUM EMPNO ENAME
--------- --------- ----------
1 7782 CLARK
2 7788 SCOTT
3 7839 KING
4 7844 TURNER
I know the nvl function only allows the same data type(ie. number or char or date
Nvl(comm, 0)), if commission is null then the text “Not Applicable” want to display, instead of
blank space. How do I write the query?
SQL> select nvl(to_char(comm.),'NA') from emp;
Output :
NVL(TO_CHAR(COMM),'NA')
-----------------------
NA
300
500
NA
1400
NA
NA
Oracle cursor : Implicit & Explicit cursors
Oracle uses work areas called private SQL areas to create SQL statements.
PL/SQL construct to identify each and every work are used, is called as Cursor.
For SQL queries returning a single row, PL/SQL declares all implicit cursors.
For queries that returning more than one row, the cursor needs to be explicitly declared.
Explicit Cursor attributes
There are four cursor attributes used in Oracle
cursor_name%Found, cursor_name%NOTFOUND, cursor_name%ROWCOUNT, cursor_name%ISOPEN
Implicit Cursor attributes
Same as explicit cursor but prefixed by the word SQL
SQL%Found, SQL%NOTFOUND, SQL%ROWCOUNT, SQL%ISOPEN
Tips : 1. Here SQL%ISOPEN is false, because oracle automatically closed the implicit cursor after
executing SQL statements.
: 2. All are Boolean attributes.
Find out nth highest salary from emp table
SELECT DISTINCT (a.sal) FROM EMP A WHERE &N = (SELECT COUNT (DISTINCT (b.sal)) FROM EMP B
WHERE a.sal<=b.sal);
Enter value for n: 2
SAL
---------
3700
To view installed Oracle version information
SQL> select banner from v$version;
Display the number value in Words
SQL> select sal, (to_char(to_date(sal,'j'), 'jsp'))
from emp;
the output like,
SAL (TO_CHAR(TO_DATE(SAL,'J'),'JSP'))
--------- -----------------------------------------------------
800 eight hundred
1600 one thousand six hundred
1250 one thousand two hundred fifty
If you want to add some text like,
Rs. Three Thousand only.
SQL> select sal "Salary ",
(' Rs. '|| (to_char(to_date(sal,'j'), 'Jsp'))|| ' only.'))
"Sal in Words" from emp
/
Salary Sal in Words
------- ------------------------------------------------------
800 Rs. Eight Hundred only.
1600 Rs. One Thousand Six Hundred only.
1250 Rs. One Thousand Two Hundred Fifty only.
Display Odd/ Even number of records
Odd number of records:
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);
1
3
5
Even number of records:
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)
2
4
6
Which date function returns number value?
months_between
Any three PL/SQL Exceptions?
Too_many_rows, No_Data_Found, Value_Error, Zero_Error, Others
What are PL/SQL Cursor Exceptions?
Cursor_Already_Open, Invalid_Cursor
Other way to replace query result null value with a text
SQL> Set NULL ‘N/A’
to reset SQL> Set NULL ‘’
What are the more common pseudo-columns?
SYSDATE, USER , UID, CURVAL, NEXTVAL, ROWID, ROWNUM
What is the output of SIGN function?
1 for positive value,
0 for Zero,
-1 for Negative value.
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