I would like to query data, which is between some week days, as follows:
Last Saturday
The Sunday before it
The Saturday before that queried Sunday on 2.
The Sunday before that queried Saturday on 3.
The query would run automatically every Monday, so I would like to set a dynamic condition for it, so that it automatically picks that days, without depending on any day it will run on in the future.
So for example if today is Monday 01/08/2018:
would be 01/06/2018
would be 12/31/2017
would be 12/30/2017
would be 12/24/2017
I would like to set that conditions in the WHERE clause. For now I am querying it this way, with constant dates for example for last week data:
SELECT *
FROM thisTable
WHERE Date(operation_date) BETWEEN '2018-06-10' AND '2018-06-16'
DBMS: Amazon Redshift
The DATE_TRUNC Function is your friend. It truncates to a Monday.
SELECT
CURRENT_DATE AS today,
DATE_TRUNC('week', CURRENT_DATE) as most_recent_monday,
DATE_TRUNC('week', CURRENT_DATE) - 2 AS most_recent_saturday,
DATE_TRUNC('week', CURRENT_DATE) - 8 AS sunday_before_most_recent_saturday
Returns:
2018-06-21 | 2018-06-18 00:00:00 | 2018-06-16 00:00:00 | 2018-06-10 00:00:00
Note that it treats the date as midnight at the beginning of the day. So, you don't really want to query Sunday to Saturday. You actually want to query Sunday to Sunday (which really means midnight at the start of Sunday to midnight at the start of the next Sunday). This assumes your source date is a timestamp.
If your source date is purely a date, then you would want to use Sunday to Saturday.
If you want to query everything from "last week" (if your definition is Sunday to Sunday), and assuming a timestamp, use:
SELECT *
FROM thisTable
WHERE operation_date BETWEEN
-- Most recent Monday minus 8 days = Two Sundays ago
DATE_TRUNC('week', CURRENT_DATE) - 8 AND
-- Most recent Monday minus 1 day = Most recent Sunday
DATE_TRUNC('week', CURRENT_DATE) - 1
(Well, unless you're on a Sunday already, but that's your problem!)
If the date is a date, you'd have to adjust it a bit.
last Sat: date_trunc('week',getdate())-interval '2 day'
prev Sat: date_trunc('week',getdate())-interval '9 day'
this is for Monday-based week
Related
I have spent days trying to figure this out to no avail, so hopefully someone can help me. I have a queried date set which contains several fields including a column of dates. What I want to do is create a new field in my query that tells what the Monday and Friday is for the week of that row's particular date.
So for example; if the date in one of my rows is "1/16/18",
the new field should indicate "1/15/18 - 1/19/18".
So basically I need to be able to extract the Monday date (1/15/18) and the Friday date (1/19/18) of the week of 1/16/18 and then concatenate the two with a dash ( - ) in between. I need to do this for every row.
How on earth do I do this? I've been struggling just to figure out how to find the Monday or Friday of the given date...
Assuming that your column is of type date, you can use trunc to get the first day of the week (monday) and then add 4 days to get the friday.
For example:
with yourTable(d) as (select sysdate from dual)
select trunc(d, 'iw'), trunc(d, 'iw') + 4
from yourTable
To format the date as a string in the needed format, you can use to_char; for example:
with yourTable(d) as (select sysdate from dual)
select to_char(trunc(d, 'iw'), 'dd/mm/yy') ||'-'|| to_char(trunc(d, 'iw') + 4, 'dd/mm/yy')
from yourTable
gives
15/01/2018-19/01/18
There may be a simpler, canonical Oracle method to this but you can still reduce it to a simple calculation on your own either way. I'm going to assume you're dealing with only dates falling Monday through Friday. If you do need to deal with weekend dates then you might have to be more explicit about which logical week they should be attached to.
<date> - (to_char(<date>, 'D') - 2) -- Monday
<date> + (6 - to_char(<date>, 'D')) -- Friday
In principle all you need to do is add/subtract the appropriate number of days based on the current day of week (from 1 - 7). There are some implicit casts going on in there and it would probably be wise to handle those better. You might also want to check into NLS settings to make sure you can rely on to_char() using Sunday as the first day of week.
https://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements004.htm
You can also use the NEXT_DAY function, as in:
SELECT TRUNC(NEXT_DAY(SYSDATE, 'MON')) - INTERVAL '7' DAY AS PREV_MONDAY,
TRUNC(NEXT_DAY(SYSDATE, 'FRI')) AS NEXT_FRIDAY
FROM DUAL;
Note that using the above, on weekends the Monday will be the Monday preceding the current date, and the Friday will be the Friday following the current date, i.e. there will be 11 days between the two days.
You can also use
SELECT TRUNC(NEXT_DAY(SYSDATE, 'MON')) - INTERVAL '7' DAY AS PREV_MONDAY,
TRUNC(NEXT_DAY(SYSDATE, 'MON')) - INTERVAL '3' DAY AS NEXT_FRIDAY
FROM DUAL;
in which case the Monday and Friday will always be from the same week, but if SYSDATE is on a weekend the Monday and Friday returned will be from the PREVIOUS week.
I'm working on a booking platform which has several different rates. These rates are determined by the time of day, day of week, and day of year. Here are some examples of the interval types involved:
Monday to Friday, 9am to 5pm
Saturday and Sunday, 12am to 9am
Saturday and Sunday, 9am to 5pm
Saturday and Sunday, 5pm to 12am
December 23rd & 24th, anytime
December 26th & 27th, anytime
What is the best way to represent this, such that it's possible to query for the different effective rates on any given day?
At the moment, the way I've done is using two array type columns, days_of_week[] and hours_of_day[], populating them with the days/hours each rate applies. To account for special cases like December, I also have fields valid_from and invalid_after, however this requires a new entry for each year.
I've had a look at the datetime functions for intervals and such here but haven't seen anything that looks like it could solve this.
why not just listing them in where clause? eg for first sample:
t=# select now(),extract('dow' from now()) between 1 and 5 and now()::time between '09:00' and '17:00';
now | ?column?
-------------------------------+----------
2017-11-27 16:56:01.544642+00 | t
so you take (extract('dow' from now()) between 1 and 5 and now()::time between '09:00' and '17:00') to brackets and add same brackets over OR...
You can addthem all to a function with timestamptz as argument and return true of false to use in where clause
Need help figuring out how to determine if the date is the same 'day' as today in teradata. IE, today 12/1/15 Tuesday, same day last year was actually 12/2/2014 Tuesday.
I tried using current_date - INTERVAL'1'Year but it returns 12/1/2014.
You can do this with a bit of math if you can convert your current date's "Day of the week" to a number, and the previous year's "Day of the week" to a number.
In order to do this in Teradata your best bet is to utilize the sys_calendar.calendar table. Specifically the day_of_week column. Although there are other ways to do it.
Furthermore, instead of using CURRENT_DATE - INTERVAL '1' YEAR, it's a good idea to use ADD_MONTHS(CURRENT_DATE, -12) since INTERVAL arithmetic will fail on 2012-02-29 and other Feb 29th leap year dates.
So, putting it together you get what you need with:
SELECT
ADD_MONTHS(CURRENT_DATE, -12)
+
(
(SELECT day_of_week FROM sys_calendar.calendar WHERE calendar_date = CURRENT_DATE)
-
(SELECT day_of_week FROM sys_calendar.calendar WHERE calendar_date = ADD_MONTHS(CURRENT_DATE, -12))
)
This is basically saying: Take the current dates day of week number (3) and subtract from it last years day of week number (2) to get 1. Add that to last year's date and you'll have the same day of the week as current date.
I tested this for all dates between 01/01/2010 and CURRENT_DATE and it worked as expected.
Why don't you simply subtract 52 weeks?
current_date - 364
The SQL below will get you to the abbreviated name for the day of week, it's cumbersome but it works across versions of Teradata.
SELECT CAST(CAST(ADD_MONTHS(CURRENT_DATE, -12) AS DATE FORMAT 'E3') AS CHAR(3)) AS LY_DayOfWeek
, CAST(CAST(CURRENT_DATE) AS DATE FORMAT 'E3') AS CHAR(3)) AS CY_DayOfWeek
Dates are internally represented at integers in Teradata as (Year-1900) * 100000 + (MONTH * 100) + DAY. You may be able to do some creative arithmetic to figure out that 12/1/2015 Tuesday was 12/2/2014 Tuesday last year.
I have a oracle db and there are two columns so i want to display day ex:(SUNDAY, MONDAY...) according to given date in db.
Table Name: TBL_HOLIDAY_MASTER:
Holiday_date Description
***********************************
22-NOV-15 Weekly Holiday
23-NOV-15 Working Day
24-NOV-15 Working Day
29-NOV-15 Weekly Holiday
30-NOV-15 Working Day
21-MAY-17 Weekly Holiday
18-AUG-19 Weekly Holiday
I want output Like:-
Holiday_date Description
*************************************
SUNDAY Weekly Holiday
MONDAY Working Day
TUESDAY Working Day
SUNDAY Weekly Holiday
MONDAY Working Day
SUNDAY Weekly Holiday
SUNDAY Weekly Holiday
You may achieve this with TO_CHAR function with DAY parameter, in your case it would be:
SELECT TO_CHAR(Holiday_date,'DAY') as Holiday_date, Description
FROM TBL_HOLIDAY_MASTER;
You need to use TO_CHAR and FMDAY format to get the day name. FM is required to remove the trailing blank spaces.
TO_CHAR(date_column, 'FMDAY', 'NLS_DATE_LANGUAGE=ENGLISH')
For example,
SQL> SELECT TO_CHAR(SYSDATE + LEVEL -1, 'FMDAY', 'NLS_DATE_LANGUAGE=ENGLISH') "DAYS"
2 FROM DUAL
3 CONNECT BY level <= 7;
DAYS
---------
MONDAY
TUESDAY
WEDNESDAY
THURSDAY
FRIDAY
SATURDAY
SUNDAY
7 rows selected.
Normally I only show a record, if the actual date is one year later than the date in the database. How can I check if that day is a friday and then show also the records with the date of the saturday or sunday?
For example: Friday the 13th before one year. I will also show records from 14th(saturday) and 15th(sunday)
where myDate.arrival < TRUNC (SYSDATE) -365)
That's my actual statement.
You need a condition in case. Check the example below for reference:
WHERE txnday in
CASE to_char(sysdate, 'Day')
WHEN 'Friday' THEN // Include condition for Sat and Sun as well
ELSE // Include condition for only that day
END
Where Mydate.Arrival < Trunc (Sysdate) - 365
Or (to_char(Mydate.Arrival, 'D') = 6 AND Mydate.Arrival < Trunc (Sysdate) -363)
This way, you can check if that day is a Friday (6th day of week) and then select records whose Arrival value is less than sysdate - 363 (2 more days - Saturday and Sunday - included).