Timestamp with timezone in PostgreSQL 9.6 - postgresql

I am currently searching my transaction table using the following query. The second TO_TIMESTAMP is specified as 2019-08-21..
SELECT t.* FROM Transaction t WHERE t.datetime >= TO_TIMESTAMP('2019-01-01T07:54:34','YYYY-MM-ddTHH:MI:SS')
AND t.datetime < TO_TIMESTAMP('2019-08-21T14:38:34','YYYY-MM-ddTHH:MI:SS') AND (t.location_1 = 2001 OR t.location_2 = 2001);
It returns me the following result:
When i change the second TO_TIMESTAMP to 2019-08-22.. It returns me the current day's result. I am not sure why I need to add one more day in order to retrieve the current day's result..
The current timezone in the PostgreSQL 9.6 is:

This is your problem:
SELECT TO_TIMESTAMP('2019-08-21T14:38:34','YYYY-MM-ddTHH:MI:SS');
to_timestamp
------------------------
2019-08-21 00:38:34+00
(1 row)
The unescaped T confuses the parser (the actual result may even be buggy).
Use the correct format string:
SELECT TO_TIMESTAMP('2019-08-21T14:38:34','YYYY-MM-DD"T"HH24:MI:SS');
to_timestamp
------------------------
2019-08-21 14:38:34+00
(1 row)

Related

How to extract Year and Month in SQL Postgres by using Data_Part function

I am facing an issue extracting the month and year from the data (in Character varying type) >> InvoiceDate in SQL Postgres. I have seen the solution is relatively easy with MySQL function: DATEFROMPARTS as per the below Code which is not available in SQLpostgres. How can I get the same result DATA_PART function in Postgres SQL, but simultaneously I need to change the data type of the column "InvoiceDate" to the date
Select
CustomerID,
min(InvoiceDate) first_purchase_date,
DATEFROMPARTS(year(min(InvoiceDate)), month(min(InvoiceDate)), 1) Cohort_Date
into #cohort
from #online_retail_main
group by CustomerID
The output:
Customer ID| first_purchase_date |Cohort_Date|
-----------+-------------------------+-----------+
12345 | 2010-12-20 15:47:00:00 | 2010-12-01|
I am trying to make a date consits of Year and Month , while the day to be set as 1 for all
Assuming a valid Postgres timestamp:
select date_trunc('month', '2010-12-20 15:47:00.00'::timestamp)::date;
date_trunc
------------
12/01/2010
--or ISO format
set datestyle = 'ISO,MDY';
select date_trunc('month', '2010-12-20 15:47:00.00'::timestamp)::date;
date_trunc
------------
2010-12-01
Uses date_trunc to truncate the timestamp to a month which means the first of the month. Then cast(::date) to a date type. The DateStyle just deals with how the value is presented to the user. The value is not stored formatted.
To do something similar to what you did in MySQL:
select make_date(extract(year from '2010-12-20 15:47:00.00'::timestamp)::integer, extract(month from '2010-12-20 15:47:00.00'::timestamp)::integer, 1);
This uses make_date from here Date/time functions and extract to build a date.

How to store mmyy in Postgres?

There are two variables:
$mm = "01";
$yy = "22";
I need to store it in one column Postges mmyy.
What is type mmyy must be if there is not day?
Or I can use the first day of month always like: 010122.
Eventually, I want to filter rows with where mmyy > now().
If you want to treat it like a date/time value, preferably store it as date. That would be:
date '2022-01-01'
Occupies only 4 bytes, same as int4.
Always use ISO format, which is unambiguous regardless of your locale settings. More in the manual.
To convert your variables, you might use the Postgres function to_date():
test=> SELECT to_date('2201', 'YYMM');
to_date
------------
2022-01-01
(1 row)
test=> SELECT to_date('22'::text || '01'::text, 'YYMM');
to_date
------------
2022-01-01
(1 row)
Or prepare a date literal in ISO format.
When compared to now() (which returns timestamp with time zone) the date value is coerced to the first instant of Jan 1st, 2022 at the time zone determined by the current setting of your session. See:
Difference between now() and current_timestamp
So it works as intended out of the box - except that you possibly haven't thought about time zones, yet ...
For other tasks with date arithmetic, an integer might be a good choice. See:
How do you do date math that ignores the year?

Converting varchar to date in postgresql (date_parse doesn't work)

Running this existing query in presto:
date(date_parse(activation_date, '%%m-%%d-%%Y')) from table1
gives the error
"Invalid format: "02/06/2022""
Activation_date is varchar, showing MM/DD/YYYY
How do I convert it to a date so that I can join it to a column that is already in postgresql date type? Thank you so much!
The expected format is %m/%d/%Y in Trino (formerly PrestoSQL).
trino> SELECT date(date_parse('02/06/2022', '%m/%d/%Y'));
_col0
------------
2022-02-06
https://trino.io/docs/current/functions/datetime.html?highlight=date_parse#mysql-date-functions
date_parse is not a Postgres function.
You don't need to escape % in Postgres strings.
Your format has - while your string has /.
If your DateStyle is set to MDY (Month Day Year), simply cast the string to a date.
# SELECT current_setting('datestyle');
current_setting
-----------------
ISO, MDY
# select '02/06/2022'::date;
date
------------
2022-02-06
See Date/Time Input for more.

Having a problem finding those records between yesterday and today based on a UTC column value using PostgreSQL

Using PostgreSQL and trying to query a table that contains a UTC column. The UTC column is a column without the timezone as I understand it from the developer. Example in my DB for a record is (2021-08-26 13:59:26.867578). And I have to search for records that are between yesterday's date and today's date. When I tried the SQL statement below I get this error:
[42883] ERROR: operator does not exist: timestamp without time zone - integer Hint: No operator matches the given name and argument types. You might need to add explicit type casts. Position: 63
Here is my SQL statement for PostgreSQL:
SELECT omd.*
FROM "OCRMetaDatas" omd
WHERE (omd."ScannedAt")-5 BETWEEN Now()-1 and now()
ORDER BY omd."ScannedAt" desc;
Any help/direction would be appreciated. Thanks.
You can't operate integer with datetimes. Here you are trying to do that twice:
(omd."ScannedAt")-5
and
Now()-1
You should use INTERVAL with datetime there, such as:
SELECT omd.*
FROM "OCRMetaDatas" omd
WHERE (omd."ScannedAt")- '5 days'::INTERVAL BETWEEN Now()- '1 day'::INTERVAL and now()
ORDER BY omd."ScannedAt" desc;
As illustration of how to use at time zone:
--My TimeZone
show TimeZone;
TimeZone
------------
US/Pacific
select '2021-08-26 13:59:26.867578'::timestamp;
timestamp
----------------------------
2021-08-26 13:59:26.867578
select '2021-08-26 13:59:26.867578'::timestamp at time zone 'UTC';
timezone
-------------------------------
2021-08-26 06:59:26.867578-07
select now();
now
-------------------------------
2021-08-26 09:23:57.818477-07
at time zone will normalize the timestamps to the same time zone.

Date comparison in Netezza does not work properly

I am trying to run a simple query that excludes all records from the table which are greater than the maximum value of a date column. e.g.
SELECT * FROM TABLE1
WHERE LD_TMSTMP > (SELECT MAX(LD_TMSTMP) FROM TABLE1)
===========================================
0 records returned
This query should return zero records and it does that. However when I try to run the inner query I get this:
SELECT MAX(LD_TMSTMP) FROM TABLE1
===========================================
2015-04-22 06:42:32
And when I put this value in the same query I get 131 records
SELECT * FROM TABLE1
WHERE LD_TMSTMP > TO_DATE('2015-04-22 06:42:32','YYYY-MM-DD HH24:MI:SS')
===========================================
131 records returned
Does anyone know why this happens? Do I need to use a better precision value when returning the date in string format?
The problem here is that you are confusing DATE with TIMESTAMP. The tipoff is in your title, which references a DATE, but your data shows you are clearly dealing with a TIMESTAMP.
From your SQL we can see you are using TO_DATE rather than TO_TIMESTAMP to convert your character representation, which unsurprisingly gives us a DATE.
TESTDB.ADMIN(ADMIN)=> select TO_DATE('2015-04-22 06:42:32','YYYY-MM-DD HH24:MI:SS');
TO_DATE
------------
2015-04-22
(1 row)
TESTDB.ADMIN(ADMIN)=> select to_timestamp('2015-04-22 06:42:32','YYYY-MM-DD HH24:MI:SS');
TO_TIMESTAMP
---------------------
2015-04-22 06:42:32
(1 row)