Functions : Functions are pre-defined programs which returns always one value

Types of Functions: 1. Single Row Functions 2. Group Functions

Single Row Functions : The function which acts on each and every row.

Types of single row functions

Characters / String Functions
Numbers Functions
Date functions
Conversion Functions

Conversion Functions

to_char
to_date
to_number

Conversion Functions : returns the converted value

to_char : Converts to character from the date or number

SQL> select to_char(sysdate,’dd’) from dual; — returns the day number from the date

TO

SQL> select to_char(sysdate,’day’) from dual;

TO_CHAR(SYSDATE,’DAY’)

friday

SQL> select to_char(sysdate,’mon’) from dual;

TO_CHAR(SYSD

apr

SQL> select to_char(sysdate,’month’) from dual;

TO_CHAR(SYSDATE,’MONTH’)

april

SQL> select to_char(sysdate,’mm’) from dual; — Returns the month number

TO

SQL> select to_char(sysdate,’yy’) from dual;

TO

SQL> select to_char(sysdate,’yyyy’) from dual;

TO_C

2015

SQL> select to_char(sysdate,’year’) from dual;

TO_CHAR(SYSDATE,’YEAR’)

twenty fifteen

SQL> select sysdate from dual;

SYSDATE

24-APR-15

SQL> select to_char(sysdate,’dd/mon/yy’) from dual;

TO_CHAR(SYSDATE,’D

24/apr/15

SQL> select to_char(sysdate,’mm-dd-yyyy’) from dual;

TO_CHAR(SY

04-24-2015

SQL> select to_char(sysdate,’day-month-year’) from dual;

TO_CHAR(SYSDATE,’DAY-MONTH-YEAR’)

friday -april -twenty fifteen

TO_NUMBER: It converts from character to number

SQL> select to_number(’56’)+60 from dual;

TO_NUMBER(’56’)+60

TO_DATE : It convers character type date format to actual date format

sql> select to_date(’12 apr 2015′) from dual;

12-apr-2015

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