Change all dates in postgresql table to previous day - postgresql

I need to go through every row in a table and set every date in a particular column to the date before its current value (minus 14 hours, previous day, etc).
I could write a script to do this but I was wondering if there was a better SQL method?
Thanks!

UPDATE yourtable SET thefield = thefield - interval '14 hour';
relevant docs here, which should have been your first place to check.

Related

How to get data according to a user defined date in Tableau?

I am creating a tableau dashboard and it should load data according to the date the user enters. This is the logic that I am trying.
select distinct XX.ACCOUNT_NUM, (A.TOTAL_BILLED_TOT-A.TOTAL_PAID_TOT)/1000 arrears, ((A.TOTAL_BILLED_TOT-A.TOTAL_PAID_TOT)/1000 - XX.SUM_BILL ) TILL_REF_JUL20
FROM
(
select /*+ parallel (bill ,40 ) */ distinct account_num, sum(INVOICE_NET_mny + INVOICE_TAX_mny)/1000 SUM_BILL
from bill
where account_num in (Select account_num from MyTable)
and trunc(bill_dtm) > ('07-Aug-2021') –-Refmonth+1 month and 07 is a constant. Only month and year is changing
and cancellation_dtm is null
group by account_num
)xx , account a
where xx.ACCOUNT_NUM = A.account_num
Here is what I tried. First created a parameter called ref_Month. Then created a calculated field with this.
[Ref_Month]=MAKEDATE(DATETRUNC('year',(DATEADD('month', 1, [Ref_Month])), 07))
But I am getting an error. I am using a live connection. Is there any method to achive this?
I don't understand what this statement is trying to do:
[Ref_Month]=MAKEDATE(DATETRUNC('year',(DATEADD('month', 1, [Ref_Month])), 07))
If Ref_Month is a date, which it has to be for DATEADD to be a valid operation, why not make it the 7th of whatever starting month and year you are starting with? Then DATEADD('month',1, [Ref_Month]) will be a month later, still on the 7th. So you don't need DATETRUNC or MAKEDATE at all.
That said, how, when, and where are you trying to COMPUTE a PARAMETER,
let alone based on itself?

How to select 24 hours old records using Postgres?

I am using this query
select * from table_nm where table_nm_date > NOW() - INTERVAL '24 hour'
But giving today's records too. Please help me.
Output : "2016-03-20 19:31:11.896159",
"2016-03-21 08:24:58.223245",
"2016-03-21 09:13:59.768953",
"2016-03-21 09:51:25.161428",
"2016-03-21 11:35:07.378706"
I only want 2016-03-20 data.
If you want yesterday's data, filter for date only:
SELECT *
FROM table_nm
WHERE table_nm_date BETWEEN CURRENT_DATE - 1 AND CURRENT_DATE
(which is an index-friendly variant of:)
WHERE table_nm_date::date = CURRENT_DATE - 1
Assuming table_nm_date is a usual date-time like data type
then your query turns down to select "any entry from the last 24 hours"
If you want to exclude "todays" records you need to exclude those in an appropriate way, e.g by using table_nm_date between START_OF_WINDOW and END_OF WINDOW, setting both borders as it suits your needs.

Firebird check if date is before 12 pm of the current day

Date calculations are not my strong point and I need a little help.
I'm trying to check if a date (which is a timestamp) from a selected field is before 12pm of the current day. Thanks in advance.
Scenario: if an order is placed before 12pm that day, it will qualify for x otherwise it gets y. So my create date (including time) of that order is what I get in my select statement.
The DATE type doesn't carry time information, so it is up to you to define at what point in time the date is. You should use TIMESTAMP type if the time information is also important.
Anyway, lets say that the field stores the date at 12pm time, then you use
WHERE date_field <= CURRENT_DATE;
CURRENT_DATE is so called context variable which returns, obviously, current date. CURRENT_TIMESTAMP and CURRENT_TIME are also available. You can use DATEADD and DATEDIFF builtin functions to do some date calculations.
So if the field is actually timestamp, you could do it like
WHERE date_field < DateAdd(12 HOUR to cast(CURRENT_DATE as timestamp));

How to update only "hour" part in a datetime field in oracle?

Is there a way to update only Hour part in a DateTime field?? If not, how do I update the time part in Oracle? I tried this->
update tab_name
set C_Name=to_date('04/03/2012 00:31:00','MM/DD/YYYY HH:MI:SS AM')
where C_Name1=10484;
didn't work as I'm updating '00' in Hour part.
If I knew I wanted to update just one part of the time I'd probably convert to a string with the value I want in the appropriate place, then convert back to a date. Say I wanted the minutes to be "31":
update tab_name
set C_Name=
to_date(
to_char(C_Name, 'MM/DD/YYYY HH24:"31":SS'),
'MM/DD/YYYY HH24:MI:SS'
)
where C_Name1=10484;
If you want to modify the time portion relative to its current value (to add 2 hours or subtract 3 seconds, for example) then there are some choices for date arithemtic. The Oracle documentation is very good for these things.

T-SQL Between Dates Confusion

I am working with T-SQL in SQL Server 2000 and I have a table TRANSACTIONS which has a date column TRANDATE defined as DateTime, among many other columns which are irrelevant for this question..
The table is populated with transactions spanning many years. I ran into code, test, that has me confused. There is a simple SELECT, like this:
SELECT TRANDATE, RECEIPTNUMBER FROM TRANSACTIONS WHERE TRANDATE BETWEEN '12/01/2010' and '12/31/2010' ORDER BY TRANDATE
and its not returning two rows of data that I know are in that table.
With the statement above, the last row its returning, in order, has a TRANDATE of:
2010-12-31 00:00:00.000
When I modify the statement like below, I get the additional two rows for December 2010 that are in that table:
SELECT TRANDATE, RECEIPTNUMBER FROM TRANSACTIONS WHERE TRANDATE BETWEEN '12/01/2010 00:00:00' and '12/31/2010 23:59:59' ORDER BY TRANDATE
I have tried to find out why the BETWEEN operator doesnt include ALL rows for the 24 period in 12/31/2010 when using the first SELECT, above. And why does it need to have the explicit hours added to the SELECT statement as in the second, modified, statement to get it to pull the correct number of rows out?
Is it because of the way TRANDATE is defined as "DATETIME"?
Based on this finding, I think that am going to have to go through all of this old code because these BETWEEN operators are littered throughout this old system and it seems like its not pulling all of the data properly. I just wanted clarification from some folks first. Thanks!
A date is a point in time, not a time span.
'12/31/2010' is a point, too. Namely, it's the midnight of the 31st of December.
Everything that happened after this point is ignored.
That's exactly the behaviour you want (even if you haven't realised that yet).
Do not think that when you choose to omit the time part, it is magically assumed to be "any". It's going to be "all zeroes", that is, the midnight.
If you want to include the entire day in your query without having to specify 23:59:59 (which, by the way, excludes the last second of the day, between the moment 23:59:59 of the current day and the moment 00:00:00 of the next day), you can do that either by using strict inequalities (>, <) bounded by the first points of time you don't want:
WHERE TRANDATE >='12/01/2010 00:00:00' and TRANDATE < '01/01/2011'
or by comparing date values casted to DATE:
WHERE CAST(TRANDATE AS DATE) between '12/01/2010' and '12/31/2010'
(it is okay to put this type of cast in a WHERE clause, it is sargable).
As you have discovered, if you don't specify a time when entering a date, it defaults to midnight in the morning of the date. So 12/31/2010 stops at midnight when that day begins.
To get all dates for 12/31/2010, you can either specify the time, as you have done, or add one day to the ending date. Without a time, 1/1/2011 ends at the stroke of midnight on 12/31/2010. So, you could do BETWEEN 12/1/2010 AND 1/1/2011. You can use DATEADD to add the day in your SQL if that makes it easier.
There is some risk in that second approach of adding a day. You will get any records for 1/1/2011 that carry the time of 00:00:00.
Here's one way to perform the DATEADD:
DECLARE #FromDate datetime, #ToDate datetime
// These might be stored procedure input parameters
SET #FromDate = '12/1/2010'
SET #ToDate = '12/31/2010'
SET #ToDate = DATEADD(d, 1, #ToDate)
Then you use #ToDate in your WHERE clause in the BETWEEN phrase in the usual way.
'12/01/2010' means '12/01/2010 00:00:00' and '12/31/2010' means '12/31/2010 00:00:00'. This is why datetime values that fall later on the day on 12/31/2010 are excluded from your query results.
What would be your expected result if I would do this
Insert "12/31/2010" into your datetime column?
Exactly: 12-31-2010 00:00:00
So why would you expect it to be different as argument for a query?
You have kind of answered your own question already. What you have observed is the way SQL Server works.
If it is confirmation you need, this MSDN document has following to say about it
When the time part is unspecified, it
defaults to 12:00 A.M. Note that a row
that contains a time part that is
after 12:00 A.M. on 1998-0105 would
not be returned by this query because
it falls outside the range.
Edit
As for your comment, a datetime essentially is a floating point value.
Following script shows what numbers SQL Server works with.
40541.9749 (12/31/2010 23:23:59) can't be included when your upper bound is 40541 (12/31/2010)
DECLARE #ADateTime1 DATETIME
DECLARE #ADateTime2 DATETIME
DECLARE #ADateTime1AsFloat FLOAT
DECLARE #ADateTime2AsFloat FLOAT
SET #ADateTime1 = '12/31/2010'
SET #ADateTime2 = '12/31/2010 23:23:59'
SET #ADateTime1AsFloat = CAST(#ADateTime1 AS FLOAT)
SET #ADateTime2AsFloat = CAST(#ADateTime2 AS FLOAT)
SELECT #ADateTime1AsFloat, #ADateTime2AsFloat