ORACLE NOTES

1. 1.create table/DESC/SELECT ->
(I)Create table sachin
(name varchar2(20),
Rollno number(5),
Address varchar2(20));
(II)to create a table from existing table or copy all the data from existing
table->
Create table b
As
(select ename,sal ,empno from emp);
(III)copy only the structure of the table not the data->
Create table b
As
(select ename,sal ,empno from emp where empno=-1);
Put any false condition at the end of the query.
(II)DESC tablename; OR DESCRIBE tablename;
4. insert values in the given table
insert into a values(1,’sachin’,40000,’gzb’)
Insert into a(empno,ename) values(2,’sachin’);
Insert into a(no,name,sal) select empno,ename,sal from emp;
Insert into a values(‘&empno’,’&ename’,’&sal’);
* Insert into a (ename,empno) select &from tablename;
Here tablename is asked by oracle at the time of running the query.
Insert into a(ename) select ename from &tablename;
Oracle will ask the table name for inserting the data.
(III)FETCHIN THE VALUE FROM TABLE
select * from tablename;
OR
Select name, code, address from tablename;
OR
Select * from &tablename;
Enter value for tablename: emp

2. OR
SQL> select a ,b, a + b, a-b from maths;
A B A+B A-B
---------- ---------- ---------- ----------
10 10 20 0
20 30 50 -10
OR
SQL> select a,b,a+b as addition,a-b as subtraction from maths;
A B ADDITION SUBTRACTION
---------- ---------- ---------- -----------
10 10 20 0
20 30 50 -10
NOTEif any airthmatic operation that includes a NULL value has NULL as a value.
Null represent an irrelevant or unknown value.
5.COMMENT ON TABLE->
COMMENT ON TABLE tablename IS ‘writer ur comment’;
*6.comment on column->
COMMENT ON COLUMN tablename IS ‘write ur comment’;
select name /* it gives the name of employees*/ from sach;
it is also a comment with in the query.
7.REMOVE COMMENT->
COMMENT ON TABLE/COLUMN tablename/columnname IS ‘’;
8.ALTER TABLE->
alter table sachin
add (address varchar2(20));
Alter table tablename
drop column address;
alter table tablename Alter table sachin
Modify column modify (address varchar2(15));
Drop constraint constraint_name;

3. Use alter table to add columns or constraints to a table,change column datatypes,sizes and
not null settings ,drop constraints ,change future storage allocation ,and update the data
dictionary to show that a backup of the table occurred at the time the statement was
executed.
TO SHOW THE CONSTRAIN NAME ->
SELECT * FROM USER_CONSTRAINTS;
9.RENAME
rename tablename1 to tablename2;
10.drop table tablename;
After drop we can not rollback and it will remove the table as well as data.IF THERE is
any view exist related with the table then it wil becomes invalid.
11.truncate table tablename;
Table wil exixt .after truncate we can not rollback it wil remove the data not the table.
12.UPDATE->UPDATE tablename
Set sal=2000,mobile=9999999999
Where empno=22 or ename=’sachin’;
This command only run for the date updation not for the column operations.
13.DELETE->
Delete from(optional) tablename
Where empno=22;
We rollback our data after delete.
14.ORDER BY--
SELECT …. SELECT ……………
ORDER BY EXPR ASC,….. ORDER BY EXPR DESC,….
ORDER BY POSITION ASC ORDER BY POSITION DESC
The order by clause specifies the order in which to display the results of a query.expr.
references one or more SELECT clause columns or FROM clause tables.Position is a
number indicating the place of a colukmn in the SELECT clause.ASC OR DESC specify
ascendin or descending order for the sort ;the default is ASC.
SQL> select ename,empno from emp order by empno desc;
ENAME EMPNO
---------- ---------------
MILLER 7934
FORD 7902
JAMES 7900

4. ADAMS 7876
TURNER 7844
KING 7839
SCOTT 7788
CLARK 7782
BLAKE 7698
MARTIN 7654
JONES 7566
WARD 7521
ALLEN 7499
SMITH 7369
NOTE=> ORDER BY cannot be used in subqueries of INSERT,UPDATE,CREATE
TABLE OR CREATE VIEW STATEMENTS.An ORDRE BY cancels the effect of a
connect by clause in the same statement.
15.GROUP BY and HAVING
SELECT LIST…..
FROM TABLE
WHERE CONDITION GROUP BY EXPR,EXPR2
HAVING CONDITION
With this clause ,SELECT computes one summary row for each group of selected rows.
Every SELECT LIST EXPRESSION must either—
(i)be a function or constant with no parameter,like SYSDATE;
(ii)contain a group function like SUM,COUNT OR MAX;
(iii)match a GROUP BY expr
THE HAVING condition sets which GROUPBY groups appear in the result.
SQL> select deptno,job,sum(sal) from emp group by deptno,job;
DEPTNO JOB SUM(SAL)
---------- --------- ----------
10 CLERK 1300
10 MANAGER 2450
10 PRESIDENT 5000
20 ANALYST 6000
20 CLERK 1900
20 MANAGER 2975
30 CLERK 950
30 MANAGER 2850
30 SALESMAN 5600
9 rows selected.

5. 16. CUBE operator
The CUBE operator is an additional switch in the GROUP BY clause in a SELECT
statement. The CUBE operator can be applied to all aggregate functions including AVG,
SUM, MAX, MIN and COUNT. It is ued to produce results set that are typically used for
cross-tabular reports. While ROLLUP produces only a fraction of possible subtotal
combinations, CUBE produces subtotals for all possible combinations of groupings
specified in the GROUP BY clause and a grand total.
The CUBE operator is used with an aggregate function to generate additional rows in a
result set. Columns included in the GROUP BY clause are cross-referenced to produce a
superset of groups. The aggregate function specified in the select list is applied to the
groups to produce summary values for the additonal superaggregate rows. The number of
extra groups in the results set is determined by the number of columns included in the
GROUP BY clause.
SELECT department_id, job)id, SUM(salary)
FROM employees
WHERE department_id < 60
GROUP BY CUBE(department_id,Job_id)
MATHEMATICAL FUNCTIONS
SQL> select distinct deptno from emp;
DEPTNO
----------
10
20
30
SQL> select max(sal) from emp;
MAX(SAL)
----------
5000
SQL> select min(sal) from emp;
MIN(SAL)
----------
800
SQL> select count(*) from emp;
COUNT(*)
----------

6. 14
SQL> select * from sam;
SALARY COMMISION
---------- ----------
123.423 6665.64566
545.3444 234.534
34.43 645.3355
SQL> select round(salary,2),round(commision,2) from sam;
ROUND(SALARY,2) ROUND(COMMISION,2)
--------------- ------------------
123.42 6665.65
545.34 234.53
34.43 645.34
SQL> select trunc(salary,3),trunc(commision,3) from sam;
TRUNC(SALARY,3) TRUNC(COMMISION,3)
--------------- ------------------
123.423 6665.645
545.344 234.534
34.43 645.335
OPERATORS->
(I) Airthmatic and character operators->
( ) ->select (x+y)
+- ->….where sal= - 400
*/ -> select sal*100
+- -> select (sal-comm)
(II) we can write a line with the help of database like--
select 'contact '||ename||' gets '||'$'||sal||' per month' from emp where empno=7369
SQL> /
contact SMITH gets $800 per month
(III) Logical operators->
NOT->
Reverse the result of a logical expression .Exception:NOT(NULL)evaluates to null.
Select……..where NOT (bal=0)
AND->
Returns TRUE if all conditions are TRUE
…………….where a=1 AND b=100;

7. SQL> SELECT ENAME FROM EMP WHERE DEPTNO=20 AND SAL>500;
ENAME
----------
SMITH
JONES
SCOTT
ADAMS
FORD
OR->
Returns TRUE if any of the conditions is TRUE
…………………..where a is null or b is null
(IV) tablename.*--Selects all columns from the table in a query
(V) ALLReturns duplicate values from a query or aggregation
(VI) DISTINCTEliminates duplicate values from the result of a query .default is
ALL.
(VII) (+)-THE PRECEDING COLUMN IS THE OUTER JOIN COLUMN IN A
JOIN.
(VIII) INTERSECT->combines queries to return all distinct rows by every
individual query.
(IX) UNION combines queries to return all distinct rows returned by any
individual query.
(X) MINUScombines queries to return all distinct rows returned by the first
query buy not the second.
(XI) UNION ALLLike union but duplicate as it is come.
Note->number of column and types of columns must be same
(XI) >ALL more than the max
(XII). <ALL Less than the min
(xIII) >ANY MORE THAN THE MIN
(XIV) <ANY LESS THAN THE MAX
(XV) IN min
( XVI ) LIKE-> the sql like operator matches part of the char string to part of the
‘pattern’ string.you can use two “wild word” matchin character in the ‘pattern’:
% matches zero or more characters(called wildcard)
_ matches exactally one character(called aposition marker)
NoteString must be in quotes.and it is case sensitive.
Example->(TO FIND EMPLOYEES WHO HAVE NAMES BEGINNING WITH ‘A’)
Select ename ,sal,mgr from emp
Where ename like ‘A%’;
ANS-> ASHUTOSH , AMAR
• (TO FIND EMPLOYEES WHO HAVE HYPHENATED NAMES)
Select ename from emp
Where ename like ‘%-%’;

8. SQL> select ename,empno from emp where
2 empno like '79%';
ENAME EMPNO
---------- ----------
JAMES 7900
FORD 7902
MILLER 7934
SQRT
SQL> SELECT SQRT(625) FROM DUAL;
SQRT(625)
----------
25
NOTEoracle does not find out the square root of the negative number because it will
give the imaginary number as ans. and oracle does not support it, so it will giver an error.
LENGTH
SQL> SELECT LENGTH ('SACHIN') FROM DUAL;
LENGTH('SACHIN')
----------------
6
SQL> SELECT LENGTH('SACHIN SHUKLA') FROM DUAL;
LENGTH('SACHINSHUKLA')
----------------------
13
SQL> select name from sach order by length(name);
NAME
--------------------
SUR
WARD
FORD
KING
SMITH
JONES
CLARK
ADAMS
JAMES
SCOTT

9. BLAKE
SACHIN
MILLER
TURNER
MARTIN
SQL> ED;
Wrote file afiedt.buf
1* SELECT LENGTH ('SACHIN') FROM DUAL
SQL> SELECT LPAD('SACHIN',8,'#') FROM DUAL;
LPAD('SA
--------
##SACHIN
SQL> SELECT RPAD('SACHIN',8,'@') FROM DUAL;
RPAD('SA
--------
SACHIN@@
17.TO CHANGE THE PASSWORD OF ORACLE
SQL> GRANT CONNECT TO SCOTT IDENTIFIED BY TIGER;
Grant succeeded.
18.SET FEEDBACK OFF/ON/SHOW
FROM THIS QUERY SQL WILL NOT DISPLAY THE NO OF ROWS SELECTED
AT THE END OF OUTCOME(ANSWER).
SQL> SET FEEDBACK ON;
SQL> SELECT ENAME FROM EMP ORDER BY ENAME;
ENAME
----------
ADAMS
ALLEN
BLAKE
CLARK
FORD
JAMES
JONES
KING

10. MARTIN
MILLER
SCOTT
SMITH
TURNER
WARD
14 rows selected.
SQL> SET FEEDBACK OFF;
SQL> SELECT ENAME FROM EMP ORDER BY ENAME;
ENAME
----------
ADAMS
ALLEN
BLAKE
CLARK
FORD
JAMES
JONES
KING
MARTIN
MILLER
SCOTT
SMITH
TURNER
WARD
SQL>
SQL> SHOW FEEDBACK;
FEEDBACK ON for 25 or more rows
19.NUMWIDTH this means that all the number columns will be five digit wide.if
you anticipate havig numbers with more than five digit numbers higher than
five.individual column in the display wil set automatically or independentally.
SQL> SHOW NUMWIDTH;
numwidth 10
SQL> SET NUMWIDTH 15;
SQL> SHOW NUMWIDTH;
numwidth 15
20.NULL AND NOT NULL
Select ename from emp where mgr is null and comm is null;
KING
SQL> SELECT ENAME FROM EMP WHERE COMM IS NOT NULL;

11. ENAME
----------
ALLEN
WARD
MARTIN
TURNER
21.IN
SQL> SELECT * FROM CLASS;
NAME SECTI
-------------------- -----
SACHIN B
SURNEDRA B
NAVJEET A
KAMLESH A
GAGAN B
SSQL> SELECT NAME FROM CLASS WHERE SECTION IN('A');
NAME
--------------------
NAVJEET
KAMLESH
2 rows selected.
SQL> SELECT NAME FROM CLASS WHERE SECTION NOT IN('B');
NAME
--------------------
NAVJEET
KAMLESH
22.BETWEEN
SQL> select ename from emp where sal between 1000 and 2000;
ENAME
----------
ALLEN
WARD
MARTIN
TURNER
ADAMS
MILLER

12. 6 rows selected.
SELECT ENAME FROM EMP WHERE DEPTNO=20 AND SAL BETWEEN 1000
AND 2000
SQL> /
ENAME
----------
ADAMS
23.EDIT/DEL
If we want to edit the command at the run time and a error is come at the given 2nd line
or any other line then if we press the DEL KEY,SO it will delete that line which was
having that error.
SQL> select ename from emp
2 wheer ename='SMITH';
wheer ename='SMITH'
*
ERROR at line 2:
ORA-00933: SQL command not properly ended
SQL> DEL;
SQL> ED;
Wrote file afiedt.buf
1* select ename from emp
SQL> ED;
Wrote file afiedt.buf
1 select ename from emp
2* WHERE ENAME='SMITH'
SQL> /
ENAME
----------
SMITH
1 row selected.
• For multiline delete we can write the command as- DEL 3 7;
It means that sql have to delete the lines between 3 to 7.
• If we want to delete the particular line then we can write it asdel 12;
24.INPUT/APPEND We can edit out command at run time with these keywords.
With the input keyword->
SQL> select ename,empno from emp;
ENAME EMPNO
---------- ----------

13. SMITH 7369
ALLEN 7499
WARD 7521
JONES 7566
MARTIN 7654
BLAKE 7698
CLARK 7782
SCOTT 7788
KING 7839
TURNER 7844
ADAMS 7876
ENAME EMPNO
---------- ----------
JAMES 7900
FORD 7902
MILLER 7934
14 rows selected.
SQL> ed;
Wrote file afiedt.buf
1* select ename,empno from emp
SQL> input where ename='SMITH';
SQL> /
ENAME EMPNO
---------- ----------
SMITH 7369
• And with the append keyword we have to just writer out text after the append
keyword and give two spaces after the append command->
SQL> ED;
Wrote file afiedt.buf
1* select ename,empno from emp
SQL> APPEND WHERE ENAME='SMITH';
1* select ename,empno from emp WHERE ENAME='SMITH'
SQL> /
ENAME EMPNO
---------- ----------
SMITH 7369

14. 25.SAVE we can save our last command as a file.we have to just write a command-
>SQL> select max(sal) from emp;
MAX(SAL)
----------
5000
SQL> save sach.sql;
Created file sach.sql
And this file will save at the position c:/oracle/bin.u can see it’s location.
26.STORE SETTING u can store the setting of ur oracle in a particular file name
SQL> store set my_setting.sql create;
Created file my_setting.sql
If u want to store another setting with the same name then use replace keyword at create
SQL> store set my_setting.sql replace;
Wrote file my_setting.sql
And these files are stored at c:/oracle/bin
27.STRING CONCATINATE STRING || STRING
SQL> SELECT UPPER('Mr..')||LOWER(ENAME) FROM EMP;
UPPER('MR.')|
-------------
MR.smith
MR.allen
MR.ward
MR.jones
MR.martin
MR.blake
MR.clark
MR.scott
MR.king
MR.turner
MR.adams
MR.james
MR.ford
MR.miller
14 rows selected.
SQL> SELECT 'SACHIN'||','||UPPER(ENAME) FROM EMP;

15. 'SACHIN'||','||UP
-----------------
SACHIN,SMITH
SACHIN,ALLEN
SACHIN,WARD
SACHIN,JONES
SACHIN,MARTIN
SACHIN,BLAKE
SACHIN,CLARK
SACHIN,SCOTT
SACHIN,KING
SACHIN,TURNER
SACHIN,ADAMS
SACHIN,JAMES
SACHIN,FORD
SACHIN,MILLER
NOTENOTICE THE NAME OF THE COLUMN NAME.AND WE CAN USE
THE OTHER QUERY FOR THE RESULT LIIKE->
Select concat(ename,empno) from emp is equivalent to select ename||empno from emp;
28.RPAD/LPAD
SQL> SELECT RPAD(ENAME,20,'.'),EMPNO FROM EMP
RPAD(ENAME,20,'.') EMPNO
-------------------- ----------
SMITH............... 7369
ALLEN............... 7499
WARD................ 7521
JONES............... 7566
MARTIN.............. 7654
BLAKE............... 7698
CLARK............... 7782
SCOTT............... 7788
KING................ 7839
TURNER.............. 7844
ADAMS............... 7876
JAMES............... 7900
FORD................ 7902
MILLER.............. 7934
14 rows selected.
SQL> SELECT LPAD(ENAME,20,'.'),EMPNO FROM EMP
LPAD(ENAME,20,'.') EMPNO
-------------------- ----------

16. ...............SMITH 7369
...............ALLEN 7499
................WARD 7521
...............JONES 7566
..............MARTIN 7654
...............BLAKE 7698
...............CLARK 7782
...............SCOTT 7788
................KING 7839
..............TURNER 7844
...............ADAMS 7876
...............JAMES 7900
................FORD 7902
..............MILLER 7934
SQL> SELECT LPAD(ENAME,20),EMPNO FROM EMP;
LPAD(ENAME,20) EMPNO
-------------------- ----------
SMITH 7369
ALLEN 7499
WARD 7521
JONES 7566
MARTIN 7654
BLAKE 7698
CLARK 7782
SCOTT 7788
KING 7839
TURNER 7844
ADAMS 7876
JAMES 7900
FORD 7902
MILLER 7934
29.UPPER/LOWER/INTICAP
SQL> SELECT ENAME,UPPER(ENAME),LOWER(ENAME),INITCAP(ENAME)
FROM EMP;
ENAME UPPER(ENAM LOWER(ENAM INITCAP(EN
---------- ---------- ---------- ----------
SMITH SMITH smith Smith
ALLEN ALLEN allen Allen
WARD WARD ward Ward
JONES JONES jones Jones
MARTIN MARTIN martin Martin
BLAKE BLAKE blake Blake

17. CLARK CLARK clark Clark
SCOTT SCOTT scott Scott
KING KING king King
TURNER TURNER turner Turner
ADAMS ADAMS adams Adams
JAMES JAMES james James
FORD FORD ford Ford
MILLER MILLER miller Miller
30.SUBSTRING(SUBSTR)
SQL> SELECT SUBSTR(NAME,4,6) FROM RAM;
SUBSTR
------
HIN SH
ENDRA
AN AGR
ESH MI
NOTE->here 4 is the initial point and we have to go upto 6th place from 4th position.
SQL> SELECT LPAD(SUBSTR(NAME,4,6),20,'.') FROM RAM;
LPAD(SUBSTR(NAME,4,6
--------------------
..............HIN SH
..............ENDRA
..............AN AGR
..............ESH MI
NOTE->SUBSTR(4,15) IS EQUAL TO SUBSTR(4).
31.FIND LETTER IN THE STRING(INSTR)
SQL> SELECT NAME,INSTR(NAME,'S') FROM RAM;
NAME INSTR(NAME,'S')
------------------------------ ---------------
SACHIN SHUKLA 1
SURENDRA SINGH; 1
GAGAN AGRAWAL; 0
RUPESH MISHRA 5
After find the first one letter in the given string if we want to find the second location of
that letter in the string then we have to run the query which is given below
SQL> SELECT NAME,INSTR(NAME,'S',1,2) FROM RAM;

18. NAME INSTR(NAME,'S',1,2)
------------------------------ -------------------
SACHIN SHUKLA 8
SURENDRA SINGH; 10
GAGAN AGRAWAL; 0
RUPESH MISHRA 10
SQL> SELECT NAME, INSTR(NAME,'SHUKLA') FROM RAM;
NAME INSTR(NAME,'SHUKLA')
------------------------------ --------------------
SACHIN SHUKLA 8
SURENDRA SINGH; 0
GAGAN AGRAWAL; 0
RUPESH MISHRA 0
Note we can also add or subtract the numbers form the instr function to change the
positon of the cursor.(instr(author,’a’) +-1);
32.SOUNDEX(FIND THE ENTRIES ,SOUNDS LIKE THE WORD)
SQL> select * from emp where soundex(ename)=soundex('alln');
EMPNO ENAME JOB MGR HIREDATE SAL COMM
DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
NOTE->it compares the word’s pronuntiation in quotations and find the word’s like that.
33.NULL
Before
SQL> select ename,comm from emp;
ENAME COMM
---------- ----------
SMITH
ALLEN 300
WARD 500
JONES
MARTIN 1400
BLAKE
CLARK
SCOTT
KING
TURNER 0

19. ADAMS
JAMES
FORD
MILLER
If we want to put some values at the null place of the commission column then we have
to write down the following query.(value=500)
After
SQL> select ename,nvl(comm,500) from emp;
ENAME NVL(COMM,500)
---------- -------------
SMITH 500
ALLEN 300
WARD 500
JONES 500
MARTIN 1400
BLAKE 500
CLARK 500
SCOTT 500
KING 500
TURNER 0
ADAMS 500
JAMES 500
FORD 500
MILLER 500
• If u want to take the average of the commission column when it was having the null
points then we have to use the following query(here null will not make problem
to find the correct answer it will choose only the values)
SQL> select avg(comm) from emp;
AVG(COMM)
----------
550