86. NUMERIC FUNCTIONS

Functions can be categorized as follows.

Ø Single row functions

Ø Group functions

SINGLE ROW FUNCTIONS

Single row functions can be categorized into five. These will be applied for each row and produces individual output for each row.

Ø Numeric functions

Ø String functions

Ø Date functions

Ø Miscellaneous functions

Ø Conversion functions

NUMERIC FUNCTIONS

Ø Abs

Ø Sign

Ø Sqrt

Ø Mod

Ø Nvl

Ø Power

Ø Exp

Ø Ln

Ø Log

Ø Ceil

Ø Floor

Ø Round

Ø Trunk

Ø Bitand

Ø Greatest

Ø Least

Ø Coalesce

a) ABS

Absolute value is the measure of the magnitude of value.

Absolute value is always a positive number.

Syntax: abs (value)

Ex:

SQL> select abs(5), abs(-5), abs(0), abs(null) from dual;

ABS(5) ABS(-5) ABS(0) ABS(NULL)

---------- ---------- ---------- -------------

5 -5 0

b) SIGN

Sign gives the sign of a value.

Syntax: sign (value)

Ex:

SQL> select sign(5), sign(-5), sign(0), sign(null) from dual;

SIGN(5) SIGN(-5) SIGN(0) SIGN(NULL)

---------- ---------- ---------- --------------

1 -1 0

c) SQRT

This will give the square root of the given value.

Syntax: sqrt (value) -- here value must be positive.

Ex:

SQL> select sqrt(4), sqrt(0), sqrt(null), sqrt(1) from dual;

SQRT(4) SQRT(0) SQRT(NULL) SQRT(1)

---------- ---------- --------------- ----------

2 0 1

d) MOD

This will give the remainder.

Syntax: mod (value, divisor)

Ex:

SQL> select mod(7,4), mod(1,5), mod(null,null), mod(0,0), mod(-7,4) from dual;

MOD(7,4) MOD(1,5) MOD(NULL,NULL) MOD(0,0) MOD(-7,4)

------------ ---------- --------------------- ----------- -------------

3 1 0 -3

e) NVL

This will substitutes the specified value in the place of null values.

Syntax: nvl (null_col, replacement_value)

Ex:

SQL> select * from student; -- here for 3^rd row marks value is null

NO NAME MARKS

--- ------- ---------

1 a 100

2 b 200

3 c

SQL> select no, name, nvl(marks,300) from student;

NO NAME NVL(MARKS,300)

--- ------- ---------------------

1 a 100

2 b 200

3 c 300

SQL> select nvl(1,2), nvl(2,3), nvl(4,3), nvl(5,4) from dual;

NVL(1,2) NVL(2,3) NVL(4,3) NVL(5,4)

---------- ---------- ---------- ----------

1 2 4 5

SQL> select nvl(0,0), nvl(1,1), nvl(null,null), nvl(4,4) from dual;

NVL(0,0) NVL(1,1) NVL(null,null) NVL(4,4)

---------- ---------- ----------------- ----------

0 1 4

f) POWER

Power is the ability to raise a value to a given exponent.

Syntax: power (value, exponent)

Ex:

SQL> select power(2,5), power(0,0), power(1,1), power(null,null), power(2,-5)

from dual;

POWER(2,5) POWER(0,0) POWER(1,1) POWER(NULL,NULL) POWER(2,-5)

-------------- -------------- ----- --------- ----------------------- ---------------

32 1 1 .03125

g) EXP

This will raise e value to the give power.

Syntax: exp (value)

Ex:

SQL> select exp(1), exp(2), exp(0), exp(null), exp(-2) from dual;

EXP(1) EXP(2) EXP(0) EXP(NULL) EXP(-2)

-------- --------- -------- ------------- ----------

2.71828183 7.3890561 1 .135335283

h) LN

This is based on natural or base e logarithm.

Syntax: ln (value) -- here value must be greater than zero which is positive only.

Ex:

SQL> select ln(1), ln(2), ln(null) from dual;

LN(1) LN(2) LN(NULL)

------- ------- ------------

0 .693147181

Ln and Exp are reciprocal to each other.

EXP (3) = 20.0855369

LN (20.0855369) = 3

i) LOG

This is based on 10 based logarithm.

Syntax: log (10, value) -- here value must be greater than zero which is positive only.

Ex:

SQL> select log(10,100), log(10,2), log(10,1), log(10,null) from dual;

LOG(10,100) LOG(10,2) LOG(10,1) LOG(10,NULL)

--------------- ----------- ------------ -----------------

2 .301029996 0

LN (value) = LOG (EXP(1), value)

SQL> select ln(3), log(exp(1),3) from dual;

LN(3) LOG(EXP(1),3)

------- -----------------

1.09861229 1.09861229

j) CEIL

This will produce a whole number that is greater than or equal to the specified value.

Syntax: ceil (value)

Ex:

SQL> select ceil(5), ceil(5.1), ceil(-5), ceil( -5.1), ceil(0), ceil(null) from dual;

CEIL(5) CEIL(5.1) CEIL(-5) CEIL(-5.1) CEIL(0) CEIL(NULL)

--------- ----------- ---------- ------------ -------- --------------

5 6 -5 -5 0

k) FLOOR

This will produce a whole number that is less than or equal to the specified value.

Syntax: floor (value)

Ex:

SQL> select floor(5), floor(5.1), floor(-5), floor( -5.1), floor(0), floor(null) from

dual;

FLOOR(5) FLOOR(5.1) FLOOR(-5) FLOOR(-5.1) FLOOR(0) FLOOR(NULL)

----------- ------------- ------------ -------------- ----------- ----------------

5 5 -5 -6 0

l) ROUND

This will rounds numbers to a given number of digits of precision.

Syntax: round (value, precision)

Ex:

SQL> select round(123.2345), round(123.2345,2), round(123.2354,2) from dual;

ROUND(123.2345) ROUND(123.2345,0) ROUND(123.2345,2) ROUND(123.2354,2)

--------------------- ------------------------ ----------------------- -----------------------

123 123 123.23 123.24

SQL> select round(123.2345,-1), round(123.2345,-2), round(123.2345,-3),

round(123.2345,-4) from dual;

ROUND(123.2345,-1) ROUND(123.2345,-2) ROUND(123.2345,-3) ROUND(123.2345,-4)

------------------------ ------------------------- ------------------------ ------------------------

120 100 0 0

SQL> select round(123,0), round(123,1), round(123,2) from dual;

ROUND(123,0) ROUND(123,1) ROUND(123,2)

----------------- ----------------- ----------------

123 123 123

SQL> select round(-123,0), round(-123,1), round(-123,2) from dual;

ROUND(-123,0) ROUND(-123,1) ROUND(-123,2)

------------------ ----------------- -------------------

-123 -123 -123

SQL> select round(123,-1), round(123,-2), round(123,-3), round(-123,-1), round(

-123,-2), round(-123,-3) from dual;

ROUND(123,-1)ROUND(123,-2) ROUND(123,-3) ROUND(-123,-1) ROUND(-123,-2)

ROUND(-123,-3)

------------- ------------- ------------- -------------- -------------- --------------------------

120 100 0 -120 -100 0

SQL> select round(null,null), round(0,0), round(1,1), round(-1,-1), round(-2,-2)

from dual;

ROUND(NULL,NULL) ROUND(0,0) ROUND(1,1) ROUND(-1,-1) ROUND(-2,-2)

----------------------- -------------- -------------- ---------------- ----------------

0 1 0 0

m) TRUNC

This will truncates or chops off digits of precision from a number.

Syntax: trunc (value, precision)

Ex:

SQL> select trunc(123.2345), trunc(123.2345,2), trunc(123.2354,2) from dual;

TRUNC(123.2345) TRUNC(123.2345,2) TRUNC(123.2354,2)

--------------------- ----------------------- -----------------------

123 123.23 123.23

SQL> select trunc(123.2345,-1), trunc(123.2345,-2), trunc(123.2345,-3),

trunc(123.2345,-4) from dual;

TRUNC(123.2345,-1) TRUNC(123.2345,-2) TRUNC(123.2345,-3) TRUNC(123.2345,-4)

------------------------ ------------------------ ----------------------- ------------------------

120 100 0 0

SQL> select trunc(123,0), trunc(123,1), trunc(123,2) from dual;

TRUNC(123,0) TRUNC(123,1) TRUNC(123,2)

---------------- ---------------- -----------------

123 123 123

SQL> select trunc(-123,0), trunc(-123,1), trunc(-123,2) from dual;

TRUNC(-123,0) TRUNC(-123,1) TRUNC(-123,2)

----------------- ----------------- -----------------

-123 -123 -123

SQL> select trunc(123,-1), trunc(123,-2), trunc(123,-3), trunc(-123,-1), trunc(

-123,2), trunc(-123,-3) from dual;

TRUNC(123,-1) TRUNC(123,-2) TRUNC(123,-3) TRUNC(-123,-1) TRUNC(-123,2) TRUNC(-

123,-3)

------------- ------------- ------------- -------------- ------------- ---------------------------------

120 100 0 -120 -123 0

SQL> select trunc(null,null), trunc(0,0), trunc(1,1), trunc(-1,-1), trunc(-2,-2) from

dual;

TRUNC(NULL,NULL) TRUNC(0,0) TRUNC(1,1) TRUNC(-1,-1) TRUNC(-2,-2)

----------------------- ------------- ------------- --------------- ----------------

0 1 0 0

n) BITAND

This will perform bitwise and operation.

Syntax: bitand (value1, value2)

Ex: SQL> select bitand(2,3), bitand(0,0), bitand(1,1), bitand(null,null), bitand(-2,-3)

from dual;

BITAND(2,3) BITAND(0,0) BITAND(1,1) BITAND(NULL,NULL) BITAND(-2,-3)

-------------- --------------- -------------- ------------------------ -----------------

2 0 1 -4

o) GREATEST

This will give the greatest number.

Syntax: greatest (value1, value2, value3 … valuen)

Ex: SQL> select greatest(1, 2, 3), greatest(-1, -2, -3) from dual;

GREATEST(1,2,3) GREATEST(-1,-2,-3)

-------------------- -----------------------

3 -1

Ø If all the values are zeros then it will display zero.

Ø If all the parameters are nulls then it will display nothing.

Ø If any of the parameters is null it will display nothing.

p) LEAST

This will give the least number.

Syntax: least (value1, value2, value3 … valuen)

Ex: SQL> select least(1, 2, 3), least(-1, -2, -3) from dual;

LEAST(1,2,3) LEAST(-1,-2,-3)

-------------------- -----------------------

1 -3

Ø If all the values are zeros then it will display zero.

Ø If all the parameters are nulls then it will display nothing.

Ø If any of the parameters is null it will display nothing.

q) COALESCE

This will return first non-null value.

Syntax: coalesce (value1, value2, value3 … valuen)

Ex: SQL> select coalesce(1,2,3), coalesce(null,2,null,5) from dual;

COALESCE(1,2,3) COALESCE(NULL,2,NULL,5)

------------------- -------------------------------

1 2

85. MULTIPLE INSERTS

We have table called DEPT with the following columns and data

DEPTNO DNAME LOC

-------- -------- ----

10 accounting new york

20 research dallas

30 sales Chicago

40 operations boston

a) CREATE STUDENT TABLE

SQL> Create table student(no number(2),name varchar(2),marks number(3));

b) MULTI INSERT WITH ALL FIELDS

SQL> Insert all

Into student values(1,’a’,100)

Into student values(2,’b’,200)

Into student values(3,’c’,300)

Select *from dept where deptno=10;

-- This inserts 3 rows

c) MULTI INSERT WITH SPECIFIED FIELDS

SQL> insert all

Into student (no,name) values(4,’d’)

Into student(name,marks) values(’e’,400)

Into student values(3,’c’,300)

Select *from dept where deptno=10;

-- This inserts 3 rows

d) MULTI INSERT WITH DUPLICATE ROWS

SQL> insert all

Into student values(1,’a’,100)

Into student values(2,’b’,200)

Into student values(3,’c’,300)

Select *from dept where deptno > 10;

-- This inserts 9 rows because in the select statement retrieves 3 records (3 inserts for

each row retrieved)

e) MULTI INSERT WITH CONDITIONS BASED

SQL> Insert all

When deptno > 10 then

Into student1 values(1,’a’,100)

When dname = ‘SALES’ then

Into student2 values(2,’b’,200)

When loc = ‘NEW YORK’ then

Into student3 values(3,’c’,300)

Select *from dept where deptno>10;

-- This inserts 4 rows because the first condition satisfied 3 times, second condition

satisfied once and the last none.

f) MULTI INSERT WITH CONDITIONS BASED AND ELSE

SQL> Insert all

When deptno > 100 then

Into student1 values(1,’a’,100)

When dname = ‘S’ then

Into student2 values(2,’b’,200)

When loc = ‘NEW YORK’ then

Into student3 values(3,’c’,300)

Else

Into student values(4,’d’,400)

Select *from dept where deptno>10;

-- This inserts 3 records because the else satisfied 3 times

g) MULTI INSERT WITH CONDITIONS BASED AND FIRST

SQL> Insert first

When deptno = 20 then

Into student1 values(1,’a’,100)

When dname = ‘RESEARCH’ then

Into student2 values(2,’b’,200)

When loc = ‘NEW YORK’ then

Into student3 values(3,’c’,300)

Select *from dept where deptno=20;

-- This inserts 1 record because the first clause avoid to check the remaining

conditions once the condition is satisfied.

h) MULTI INSERT WITH CONDITIONS BASED, FIRST AND ELSE

SQL> Insert first

When deptno = 30 then

Into student1 values(1,’a’,100)

When dname = ‘R’ then

Into student2 values(2,’b’,200)

When loc = ‘NEW YORK’ then

Into student3 values(3,’c’,300)

Else

Into student values(4,’d’,400)

Select *from dept where deptno=20;

-- This inserts 1 record because the else clause satisfied once

i) MULTI INSERT WITH MULTIBLE TABLES

SQL> Insert all

Into student1 values(1,’a’,100)

Into student2 values(2,’b’,200)

Into student3 values(3,’c’,300)

Select *from dept where deptno=10;

-- This inserts 3 rows

** You can use multi tables with specified fields, with duplicate rows, with conditions,

with first and else clauses.

84. USING MERGE

MERGE

You can use merge command to perform insert and update in a single command.

Ex:

SQL> Merge into student1 s1

Using (select *From student2) s2

On(s1.no=s2.no)

When matched then

Update set marks = s2.marks

When not matched then

Insert (s1.no,s1.name,s1.marks)

Values(s2.no,s2.name,s2.marks);

In the above the two tables are with the same structure but we can merge different structured tables also but the datatype of the columns should match.

Assume that student1 has columns like no,name,marks and student2 has columns like no,

name, hno, city.

SQL> Merge into student1 s1

Using (select *From student2) s2

On(s1.no=s2.no)

When matched then

Update set marks = s2.hno

When not matched then

Insert (s1.no,s1.name,s1.marks)

Values(s2.no,s2.name,s2.hno);

83. USING ALIASES

CREATE WITH SELECT

We can create a table using existing table [along with data].

Syntax:

Create table <new_table_name> [col1, col2, col3 ... coln] as select * from

<old_table_name>;

Ex:

SQL> create table student1 as select * from student;

Creating table with your own column names.

SQL> create table student2(sno, sname, smarks) as select * from student;

Creating table with specified columns.

SQL> create table student3 as select no,name from student;

Creating table with out table data.

SQL> create table student2(sno, sname, smarks) as select * from student where 1 = 2;

In the above where clause give any condition which does not satisfy.

INSERT WITH SELECT

Using this we can insert existing table data to a another table in a single trip. But the table structure should be same.

Syntax:

Insert into <table1> select * from <table2>;

Ex: SQL> insert into student1 select * from student;

Inserting data into specified columns

SQL> insert into student1(no, name) select no, name from student;

COLUMN ALIASES

Syntax:

Select from

_name>;

Ex: SQL> select no sno from student;

SQL> select no “sno” from student;

TABLE ALIASES

If you are using table aliases you can use dot method to the columns.

Syntax:

Select <alias_name>.<col1>, <alias_name>.<col2> … <alias_name>.<coln> from

<table_name> <alias_name>;

Ex: SQL> select s.no, s.name from student s;

82. USING DCL

DCL commands are used to granting and revoking the permissions.

USING GRANT

This is used to grant the privileges to other users.

Syntax:

Grant <privileges> on <object_name> to <user_name> [with grant option];

Ex:

SQL> grant select on student to sudha; -- you can give individual privilege

SQL> grant select, insert on student to sudha; -- you can give set of privileges

SQL> grant all on student to sudha; -- you can give all privileges

The sudha user has to use dot method to access the object.

SQL> select * from saketh.student;

The sudha user can not grant permission on student table to other users. To get this

type of option use the following.

SQL> grant all on student to sudha with grant option;

Now sudha user also grant permissions on student table.

USING REVOKE

This is used to revoke the privileges from the users to which you granted the privileges.

Syntax:

Revoke <privileges> on <object_name> from <user_name>;

Ex:

SQL> revoke select on student form sudha; -- you can revoke individual privilege

SQL> revoke select, insert on student from sudha; -- you can revoke set of privileges

SQL> revoke all on student from sudha; -- you can revoke all privileges

81. USING TCL

USING COMMIT

This will be used to save the work.

Commit is of two types.

Ø Implicit

Ø Explicit

a) IMPLICIT

This will be issued by oracle internally in two situations.

Ø When any DDL operation is performed.

Ø When you are exiting from SQL * PLUS.

b) EXPLICIT

This will be issued by the user.

Syntax:

Commit or commit work;

* When ever you committed then the transaction was completed.

USING ROLLBACK

This will undo the operation.

This will be applied in two methods.

Ø Upto previous commit

Ø Upto previous rollback

Syntax:

Roll or roll work;

Rollback or rollback work;

* While process is going on, if suddenly power goes then oracle will rollback the transaction.

USING SAVEPOINT

You can use savepoints to rollback portions of your current set of transactions.

Syntax:

Savepoint <savepoint_name>;

Ex:

SQL> savepoint s1;

SQL> insert into student values(1, ‘a’, 100);

SQL> savepoint s2;

SQL> insert into student values(2, ‘b’, 200);

SQL> savepoint s3;

SQL> insert into student values(3, ‘c’, 300);

SQL> savepoint s4;

SQL> insert into student values(4, ‘d’, 400);

Before rollback

SQL> select * from student;

NO NAME MARKS

--- ------- ----------

1 a 100

2 b 200

3 c 300

4 d 400

SQL> rollback to savepoint s3;

SQL> rollback to s3;

This will rollback last two records.

SQL> select * from student;

NO NAME MARKS

--- ------- ----------

1 a 100

2 b 200

80. USING DDL

USING ALTER

This can be used to add or remove columns and to modify the precision of the datatype.

a) ADDING COLUMN

Syntax:

alter table <table_name> add <col datatype>;

Ex:

SQL> alter table student add sdob date;

b) REMOVING COLUMN

Syntax:

alter table <table_name> drop <col datatype>;

Ex:

SQL> alter table student drop column sdob;

c) INCREASING OR DECREASING PRECISION OF A COLUMN

Syntax:

alter table <table_name> modify <col datatype>;

Ex:

SQL> alter table student modify marks number(5);

* To decrease precision the column should be empty.

d) MAKING COLUMN UNUSED

Syntax:

alter table <table_name> set unused column <col>;

Ex:

SQL> alter table student set unused column marks;

Even though the column is unused still it will occupy memory.

d) DROPPING UNUSED COLUMNS

Syntax:

alter table <table_name> drop unused columns;

Ex:

SQL> alter table student drop unused columns;

* You can not drop individual unused columns of a table.

e) RENAMING COLUMN

Syntax:

alter table <table_name> rename column <old_col_name> to <new_col_name>;

Ex:

SQL> alter table student rename column marks to smarks;

USING TRUNCATE

This can be used to delete the entire table data permanently.

Syntax:

truncate table <table_name>;

Ex:

SQL> truncate table student;

USING DROP

This will be used to drop the database object;

Syntax:

Drop table <table_name>;

Ex:

SQL> drop table student;

USING RENAME

This will be used to rename the database object;

Syntax:

rename table_name

> to <new_table_name>;

Ex:

SQL> rename student to stud;

79. USING DML

USING UPDATE

This can be used to modify the table data.

Syntax:

Update <table_name> set <col1> = value1, <col2> = value2 where <condition>;

Ex:

SQL> update student set marks = 500;

If you are not specifying any condition this will update entire table.

SQL> update student set marks = 500 where no = 2;

SQL> update student set marks = 500, name = 'Venu' where no = 1;

USING DELETE

This can be used to delete the table data temporarily.

Syntax:

Delete <table_name> where <condition>;

Ex:

SQL> delete student;

If you are not specifying any condition this will delete entire table.

SQL> delete student where no = 2;

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MERGE