Partial usage of oracle date function

ORACLE Date and Time Functions

Date and character conversion function usage (to_date,to_char)

select to_char(sysdate,'y-mm-dd hh34:mi: ss') as nowTime from dual; //date converted to string

select to_char(sysdate,'y') as nowYear from dual; //get the year of the time

select to_char(sysdate,'mm') as nowMonth from dual; //get month of time

select to_char(sysdate,'dd') as nowDay from dual; //get the day of the time

select to_char(sysdate,'hh34') as nowHour from dual; //get time when

select to_char(sysdate,'mi') as nowMinute from dual; //Get the minutes of the time

select to_char(sysdate,'ss') as nowSecond from dual; //Get the seconds of the time

Ask what day of the week it is.

SQL> select to_char(to_date('2015-10-27','yyyy-mm-dd'),'day') from dual;

TO_CHA

------

Tuesday

Number of days between two days

SQL> select floor(sysdate - to_date('20020405','yyyymmdd')) from dual;

FLOOR(SYSDATE-TO_DATE('20020405','YYYYMMDD'))

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

4949

Date of treatment

select older_date,

newer_date,

years,

months,

abs(

trunc(

newer_date-

add_months( older_date,years*12+months )

)

) days from ( select

trunc(months_between( newer_date, older_date )/12) YEARS,

mod(trunc(months_between( newer_date, older_date )),12 ) MONTHS,

newer_date,

older_date

from (

select hiredate older_date, add_months(hiredate,rownum)+rownum newer_date

from emp

)

)

Ways to deal with the uncertainty of the number of days in the month

select to_char(add_months(last_day(sysdate) +1, -2), 'yyyymmdd'),last_day(sysdate) from dual

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