Which function is used to find the difference between two dates ?

You can just subtract them. Here's an example.

declare
 date1 date;
 date2 date;
 date3 number(7,2);
begin
 select sysdate into date1 from dual;
 select (sysdate-30) into date2 from dual;
 date3:= date1 - date2;
 dbms_output.put_line('Date1:' || date1 || '  Date2:' || date2 || '  Date3:' || date3);
end;
/

If you are looking for datediff like in MSSQL it does not exist.

You can use the function below (probably from tom kyte) you can also edit it for your own use

create or replace function datediff( p_what in varchar2, p_d1 in date, p_d2 in date ) return number as l_result number; begin select (p_d2-p_d1) * decode( upper(p_what), 'SS', 24*60*60, 'MI', 24*60, 'HH', 24, NULL ) into l_result from dual;

 return l_result;

end; /

call it like

SQL> select datediff('hh',sysdate-50,sysdate) from dual 2 ;

DATEDIFF('HH',SYSDATE-50,SYSDATE)

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I got the answer for this question. It is MONTHS_BETWEEN function.

SELECT MONTHS_BETWEEN('01-AUG-01','01-JAN-01') AS MONTHS_BETWEEN FROM Dual;

MONTHS_BETWEEN

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