I'm trying to create a function that returns the day of the week for a specified date, and I tried the one that's on the bottom, but unsuccessful.
SELECT DAYOFWEEK(‘2015-07-04’);
Use TO_CHAR for that.
select
to_char(date'2015-07-04', 'Day'),
to_char(date'2015-07-04', 'Day', 'NLS_DATE_LANGUAGE=american'),
to_char(date'2015-07-04', 'Day', 'NLS_DATE_LANGUAGE=german'),
to_char(date'2015-07-04', 'DY'),
to_char(date'2015-07-04', 'D') -- result depends on NLS_TERRITORY which you cannot specify here unfortunately
from dual;
The string delimiter in SQL is ', but I guess that was just a copy & paste error? A date literal in Oracle starts with DATE. To select a single value in Oracle, select from DUAL. You can optionally specify a language when you want to see weekday names. As to the day number, this depends on a session setting, unfortunately, with 1 being either Sunday or Monday.
Try:
select to_char(to_date('2015-07-04','yyyy-dd-mm'), 'DAY')
I think it should work.
Referred from:
How to get the week day name from a date?
Related
I'm using oracle dbms and I have in Employe table a column Birthdate. I want to write a query that shows the employees who has a birthday next week.
Is this correct ?
select name
from employe
where to_char(birthdate,'DD-MM')=to_char(next_day(sysdate,1)+7,'DD-MM');
That is not the correct usage of next_day(): that function returns the date of the the next instance of a day. For example, to find the date of next Friday:
select next_day(sysdate, 'FRIDAY') from dual;
To find employees whose birthday is seven days from now, you need to just tweak your query a bit:
select name
from employe
where to_char(birthdate,'DD-MM') = to_char(sysdate+7,'DD-MM');
The correct solution would be
SELECT name
FROM employe
WHERE to_char(birthdate
/* "move" the birthdate to the current year
to get a reliable week number */
+ CAST((EXTRACT(year FROM current_date)
- EXTRACT(year FROM birthdate)) || '-0'
AS INTERVAL YEAR TO MONTH),
'IW')
= to_char(current_date + 7, 'IW');
The IW format returns the ISO week containing the date, which is probably what you are looking for. If you start your week on Sunday, add one to both dates.
Am getting the below issue when am using 'mon-d-yyyy' to convert date to char, as i need a single day digit for values from 1 to 9 days in a month.
When i use the 'mon-d-yyyy' format, am losing out on 5 days and getting a wrong date. Any help on this would be great.
select to_char(sysdate-22,'mon-d-yyyy') from dual;--aug-2-2017
select to_char(sysdate-22,'mon-dd-yyyy') from dual;--aug-07-2017
select sysdate-22 from dual;--07-AUG-17 11.06.43
In Oracle date formats, d gets the day of week. The 2 in your output means monday, not august the 2nd.
Try using Fill Mode as Format Model Modifier
select to_char(sysdate-22,'mon-fmdd-yyyy') from dual;
One option might be to piece together the date output you want:
SELECT
TO_CHAR(sysdate-22, 'mon-') ||
TRIM(LEADING '0' FROM TO_CHAR(sysdate-22, 'dd-')) ||
TO_CHAR(sysdate-22, 'yyyy')
FROM dual;
The middle term involving TRIM strips off the leading zeroes, if present, from the date.
Output:
Demo here:
Rextester
SQL>SELECT TO_CHAR(TO_DATE('29-AUG-2017','DD-MON-YYYY') - 22,'"WEEKDAY :"D, MON-FMDD-YYYY') "Before22Days" FROM DUAL;
D- Gives you a numeric weekday(2nd weekday in a week) on AUG-07-2017.
DD-Gives a Numeric Month Day i.e,07th
FMDD-Gives 7th
Before22Days
----------------------
WEEKDAY :2, AUG-7-2017
Here's the complete code:
SELECT last_name, hire_name, To_char(hired_date, 'DAY') "Day"
from employees
order by to_char(hire_date -1,'d')
I want to understand this part of the code.
to_char (hire_date -1, 'd')
Can someone explain me how does the to_char function work?
this is oracle.
What happens ( as far as i get it) is that it takes the day of a date minus one day. Hope this helps you understand it.
So,
TO_Char(hired_date -1, day)
T0_Char = method name
hired_date = orginional date
-1 = orignional date minus 1 day
day = return the the day ( Sunday , Monday wensday)
TO_CHAR is just a converter for the type coming out of the select query, chances are that the data can't be interrogated properly without conversion, the -1 bit (if that's also confusing you) is going to give you the day before the hire date.
Given a field in Oracle that contains dates, how would you calculate what the week ending date is using Sun thru Sat as your week. For example, if the date is 1/26/2015 (which is a Monday), the query should return 1/31/2015 (which is a Saturday. If the date is 1/31/2015, then the query should return 1/31/2015.
Given any particular date / time value, this expression will return midnight of the preceding Sunday.
TRUNC(whatever_time,'DAY')
So, you can do stuff like this:
SELECT TRUNC(whatever_time,'DAY') week_starting,
TRUNC(whatever_time,'DAY') + 6 week_ending,
SUM(sales)
FROM table
GROUP BY TRUNC(whatever_time,'DAY')
and you'll get what you need.
Notice that TRUNC(whatever_time,'DAY') honors the Oracle session initialization parameter called “NLS_TERRITORY”. For example, in Europe Monday is considered the first business day of the week. Try this.
ALTER SESSION SET NLS_TERRITORY=GERMANY;
SELECT TRUNC( DATE '2013-12-31', 'DAY'),
TRUNC( DATE '2014-01-03', 'DAY')
FROM DUAL;
A complete writeup of this is here: http://www.plumislandmedia.net/sql-time-processing/using-sql-report-time-intervals-oracle/
i want to convert date to some other format.
Below is the example 04/03/10 09:00:50.000000000 AMto YYYYMM
Iam not able to get this , below is the query which i used to convert.
select to_char(to_date('04/03/10 09:00:50.000000000 AM','MM/DD/YYYY HH:MM:SS AM'),'YYYYMM') from table;
Iam getting exception as below
ORA-01810: format code appears twice
01810. 00000 - "format code appears twice"
Format Code for Minutes is MI, not MM. MM is for months.
You are using 2-digit year. Better to use RR for this. Even better use 4-digit year.
TO_DATE doesn't store fractional seconds. You need to use TO_TIMESTAMP and use the FF as format code.
So, your query would be
select to_char(to_timestamp('04/03/10 09:00:50.000000000 AM','MM/DD/RR HH:MI:SS.FF9 AM'),'YYYYMM')
from table;
To achieve your goal there are many issues to resolve ;)
Finally I made this like that:
select to_char(
to_timestamp('04/03/10 09:00:50.000000000 AM','MM/DD/YYYY HH:MI:SS.FF9 PM',
'nls_date_language = ENGLISH'),
'YYYYMM') from dual;