I can get week number using extract dow function in netezza for a date.
Select extract(Dow from date) from table
How can I get name of the weekday?
I haven't tried with a date datatype, but to get the day name from a timestamp you would use
select to_char(date, 'Day') from table
That should give results of Sunday, Monday, Tuesday, etc. Try it with your date column and please let us know if it works.
Related
How can I get a date using the week of the year in Oracle SQL?
I need to search for entries created after the beginning of the current week. Currently, I get the week of the year by doing select to_char(sysdate,'WW') from dual;, but then I can't do
select * from table where date > to_date(to_char(sysdate,'WW'), 'WW') because I get
ORA-01820: format code cannot appear in date input format
01820. 00000 - "format code cannot appear in date input format"
*Cause:
*Action:
You don't need to convert to a string and back, you can use truncate:
select * from table where date > trunc(sysdate,'WW')
Read more about the trunc() function and how the format model is applied.
Notice that WW gives you the same day as the first day of the year, so right now that would give 2020-09-02, which is a Wednesday - possibly not what you'd expect. It depends on your requirements of course, but you might want to work with IW which always starts from Monday, and would give 2020-09-07. If you have a different start day you can add or subtract a day, e.g. if your week starts on Sunday.
According to ORA-doc:
ORA-01820: format code cannot appear in date input format
Cause: A date specification contained an invalid format code. Only the following may > be specified when entering a date: year, month, day, hours, minutes, seconds, Julian day, > A.M./P.M. and B.C./A.D.
Action: Remove the invalid format code from the date specification.
You can't pass the weeknum to to_date() function. What you can do is e.g., the following
select * from table where date > (next_day(trunc(sysdate), 'SUNDAY') - 7)
Basically, next_day returns first date that meets specified weekday. Let's assume it's Monday 2020-09-07, next_day will return you the closest SUNDAY in the future, that is 2020-09-13, so you need to substract 7 to get date of the current week beginning. You can read more about it here
I have a date column called day such as 2019/07/22 if I want to create a custom field that translates that date to the actual day of week it is such as Sunday or Monday how is this possible? I cant seem to find a method that works for presto sql.
Thanks for looking
You can use the format_datetime function to extract the day of week from a date or timestamp:
SELECT format_datetime(day, 'E')
FROM (
VALUES DATE '2019-07-22'
) t(day)
produces:
_col0
-------
Mon
If you want the full name of the day, use format_datetime(day, 'EEEE'):
_col0
-------
Monday
You can try extract('day' from day ) as day_name.
I have a timestamp column in my table, out of which i want to create a new column - day of week - (Ex. Monday, Tuesday ) to the table. I'm using PGAdmin4
This will get the day of the week, replace GETDATE() with your timestamp.
SQL Server
SELECT DATENAME(dw,GETDATE())
PostgreSQL
select to_char(now(), 'Day')
I have a transdate column of varchar2 type which has the following entrees
01/02/2012
01/03/2012
etc.
I converted it in to date format in another column using to_date function. This is the format i got.
01-JAN-2012
03-APR-2012
When I'm trying to extract the weekno, i'm getting all null values.
select to_char(to_date(TRANSDATE), 'w') as weekno from tablename.
null
null
How to get weekno from date in the above format?
After converting your varchar2 date to a true date datatype, then convert back to varchar2 with the desired mask:
to_char(to_date('01/02/2012','MM/DD/YYYY'),'WW')
If you want the week number in a number datatype, you can wrap the statement in to_number():
to_number(to_char(to_date('01/02/2012','MM/DD/YYYY'),'WW'))
However, you have several week number options to consider:
WW Week of year (1-53) where week 1 starts on the first day of the year and continues to the seventh day of the year.
W Week of month (1-5) where week 1 starts on the first day of the month and ends on the seventh.
IW Week of year (1-52 or 1-53) based on the ISO standard.
Try to replace 'w' for 'iw'.
For example:
SELECT to_char(to_date(TRANSDATE, 'dd-mm-yyyy'), 'iw') as weeknumber from YOUR_TABLE;
Select last_name, round (sysdate-hire_date)/7,0) as tuner
from employees
Where department_id = 90
order by last_name;
Use 'dd-mon-yyyy' if you are using the 2nd date format specified in your answer. Ex:
to_date(<column name>,'dd-mon-yyyy')
I was looking up a way to solve the following:
Display the Week (eg: 1-52), start and end date of that week and a count of something.
The week, was figured to be something like: to_Char(, 'WW')
but i dont know how to get the first and last date of those weeks.
How do i do that with SqlPlus?
Edit:
Given: a table that contains a column of dates.
Try something like this:
SELECT to_char(date_col, 'iw') w, trunc(date_col, 'd') st, trunc(date_col, 'd')+6 et
FROM your_table
Here is a sqlfiddle demo
References:
TRUNC (date)
ROUND and TRUNC Date Functions
For the first date of the week, try next_day(dateColumn-8, 'Monday')
For the last date of the week, try next_day(dateColumn-1, 'Sunday')