When defining a schema in prisma, providing now() as default datetime field value is possible.
Is it possible to provide now()+ 1 year as default ?
All my attemps have failed.
You can use the dbgenerated() function to call native database functions and assign the return value as the default value of a certain field in your Prisma model.
If you're using PostgreSQL, your Prisma schema would look like this:
model foo {
id Int #id
createdAt DateTime #default(dbgenerated("NOW() + interval '1 year'")) // Default value is 1 year from now.
// ... other fields
}
Related
I just wanted to know the difference between these two codes:
select count (user_id) from tb_users where
creation_date :: date between '2022-05-15' and '2022-06-15'
Result: 41,232
select count (user_id) from tb_users where
creation_date between '2022-05-15' and '2022-06-15'
Result: 40,130
As far as I see, it is related with the timestamp, but I do not understand the difference.
Thank you!
Your column creation_date in the table is most probably in timestamp format, which is '2022-05-15 00:00:00'. By adding ::date <- you are casting your timestamp format to date format: '2022-05-15'.
You can read more about casting data types here:
https://www.postgresqltutorial.com/postgresql-tutorial/postgresql-cast/
When you ask Postgres to implicitly coerce a DATE value to a TIMESTAMP value - the hours, minutes and seconds are set to zero.
In the first query, you explicitly cast the creation date to DATE which is successfully compared to the provided DATE values.
In the second query, the creation date is of type TIMESTAMP and so PostgreSQL converts your DATE values to TIMESTAMP values and the comparison becomes
creation_date >= '2022-05-15 00:00:00' AND creation_date <= '2022-06-15 00:00:00'
Obviously, this produces different resultset than the first query.
I am looking for a function in PostgreSQL which help me to generate recurring date after every 90 days from created date
for example: here is a demo table of mine.
id date name
1 "2020-09-08" "abc"
2 "2020-09-08" "xyz"
3 "2020-09-08" "def"
I need furure date like 2020-12-08, 2021-03-08, 2021-06-08, and so on
First it's important to note that, if you happen to have a date represented as text, then you can convert it to a date via:
SELECT TO_DATE('2017-01-03','YYYY-MM-DD');
So, if you happen to have a text as an input, then you will need to convert it to date. Next, you need to know that if you have a date, you can add days to it, like
SELECT CURRENT_DATE + INTERVAL '90 day';
Now, you need to understand that you can use dynamic variables, like:
select now() + interval '1 day' * 180;
Finally, you will need a temporary table to generate several values described as above. Read more here: How to return temp table result in postgresql function
Summary:
create a function
that generates a temporary table
where you insert as many records as you like
having the date shifted
and converting text to date if needed
You can create a function that returns a SETOF dates/timestamps. The below function takes 3 parameters: a timestamp, an interval, the num_of_periods desired. It returns num_of_periods + 1 timestamps, as it returns the original timestamp and the num_of_periods each the specified interval apart.
create or replace
function generate_periodic_time_intervals
( start_date timestamp
, period_length interval
, num_of_periods integer
, out gen_timestamp timestamp
)
returns setof timestamp
language sql
immutable strict
as $$
select (start_date + n * period_length)::timestamp
from generate_series(0,num_of_periods) gs(n)
$$;
For your particular case to timestamp/date as necessary. The same function would work for your case with the interval specified as '3 months' or of '90 days'. Just a note the interval specified can be any valid INTERVAL data type. See here. It also demonstrates the difference between 3 months and 90 days.
i am trying to insert CURRENTDATE as the value for a field that has the type defined as "Timestamp without Timezone".
INSERT INTO monthly_forecasts VALUES
('1','DIV1','Mon','Tue','Wed','Thu','Fri','','','','','-3',CURRENTDATE, CURRENTDATE)
But I get this error when I do that:
ERROR: column "currentdate" does not exist
LINE 2: ...'Mon','Tue','Wed','Thu','Fri','','','','','-3',CURRENTDAT...
^
How do I insert current date as the value for this field? Please help!
As documented in the manual the function is named current_date, not currentdate.
But as your column is defined as timestamp, you should use current_timestamp to include the time of the day (a DATE doesn't have a time)
I've a calculated field in Tableau which has the Years (Date Value) from a date field. When I compare this calculated field with year of another field, I get error.
IF calculated_Field = YEAR(order_date)
...
1) calculated_Field is the one created using Date value of another field.
2) Order_date is a datetime field.
Error I see in the above IF statement says "Cant compare YEAR and INT values".
When I solved that using below statement, it does not work as expected as IF returns FALSE.
IF INT(calculated_Field) = YEAR(order_date)
Ensure the comparisons are both from YEAR()
IF YEAR(another_field) = YEAR(order_date)
calculated_Field is created using Date value of another_field.
Order_date is a datetime field.
What's the easiest way to update a table that contains a DATETIME column on TSQL with RANDOM value between 2 dates?
I see various post related to that but their Random values are really sequential when you ORDER BY DATE after the update.
Assumptions
First assume that you have a database containing a table with a start datetime column and a end datetime column, which together define a datetime range:
CREATE DATABASE StackOverflow11387226;
GO
USE StackOverflow11387226;
GO
CREATE TABLE DateTimeRanges (
StartDateTime DATETIME NOT NULL,
EndDateTime DATETIME NOT NULL
);
GO
ALTER TABLE DateTimeRanges
ADD CONSTRAINT CK_PositiveRange CHECK (EndDateTime > StartDateTime);
And assume that the table contains some data:
INSERT INTO DateTimeRanges (
StartDateTime,
EndDateTime
)
VALUES
('2012-07-09 00:30', '2012-07-09 01:30'),
('2012-01-01 00:00', '2013-01-01 00:00'),
('1988-07-25 22:30', '2012-07-09 00:30');
GO
Method
The following SELECT statement returns the start datetime, the end datetime, and a pseudorandom datetime with minute precision greater than or equal to the start datetime and less than the second datetime:
SELECT
StartDateTime,
EndDateTime,
DATEADD(
MINUTE,
ABS(CHECKSUM(NEWID())) % DATEDIFF(MINUTE, StartDateTime, EndDateTime) + DATEDIFF(MINUTE, 0, StartDateTime),
0
) AS RandomDateTime
FROM DateTimeRanges;
Result
Because the NEWID() function is nondeterministic, this will return a different result set for every execution. Here is the result set I generated just now:
StartDateTime EndDateTime RandomDateTime
----------------------- ----------------------- -----------------------
2012-07-09 00:30:00.000 2012-07-09 01:30:00.000 2012-07-09 00:44:00.000
2012-01-01 00:00:00.000 2013-01-01 00:00:00.000 2012-09-08 20:41:00.000
1988-07-25 22:30:00.000 2012-07-09 00:30:00.000 1996-01-05 23:48:00.000
All the values in the column RandomDateTime lie between the values in columns StartDateTime and EndDateTime.
Explanation
This technique for generating random values is due to Jeff Moden. He wrote a great article on SQL Server Central about data generation. Read it for a more thorough explanation. Registration is required, but it's well worth it.
The idea is to generate a random offset from the start datetime, and add the offset to the start datetime to get a new datetime in between the start datetime and the end datetime.
The expression DATEDIFF(MINUTE, StartDateTime, EndDateTime) represents the total number of minutes between the start datetime and the end datetime. The offset must be less than or equal to this value.
The expression ABS(CHECKSUM(NEWID())) generates an independent random positive integer for every row. The expression can have any value from 0 to 2,147,483,647. This expression mod the first expression gives a valid offset in minutes.
The epxression DATEDIFF(MINUTE, 0, StartDateTime) represents the total number of minutes between the start datetime and a reference datetime of 0, which is shorthand for '1900-01-01 00:00:00.000'. The value of the reference datetime does not matter, but it matters that the same reference date is used in the whole expression. Add this to the offset to get the total number of minutes between the reference datetime.
The ecapsulating DATEADD function converts this to a datetime value by adding the number of minutes produced by the previous expression to the reference datetime.
You can use RAND for this:
select cast(cast(RAND()*100000 as int) as datetime)
from here
Sql-Fiddle looks quite good: http://sqlfiddle.com/#!3/b9e44/2/0