Postgresql- Select Multiple rows dynamically from a single row

I have a column called month frequency(freq_mnth). If frequency is 3 for a row, the record has to be shown 4 times to complete one year plan with the date counting 3 months + for every record

Likewise of the frequency is 4, the record has to be shown 3 times with the date counting 4 months +

And if frequency is 12, show the record as is

I have a following table

I need the following result set

Thanks,
Ramya

I don't quite have a solution for you as I don't understand the exact requirements, but you can use generate_series to simply expand a query result to a certain number of rows representing each original row.

CREATE TABLE dates
    ("id" int, "mdate" date, "freq_mnth" int)
;
    
INSERT INTO dates
    ("id", "mdate", "freq_mnth")
VALUES
    (1, '2023-01-01', 3),
    (2, '2023-01-01', 12),
    (3, '2023-01-01', 4)
;


select dates.id
, dates.mdate 
 , (dates.mdate + (((generate_series(1,12/freq_mnth)-1)*12/freq_mnth)::text ||' month')::interval)::date as array_value_used_with_time
, generate_series(1,12/freq_mnth) as array_value
from dates

Which provides output:

id	mdate	array_value_used_with_time	array_value
1	2023-01-01	2023-01-01	1
1	2023-01-01	2023-05-01	2
1	2023-01-01	2023-09-01	3
1	2023-01-01	2024-01-01	4
2	2023-01-01	2023-01-01	1
3	2023-01-01	2023-01-01	1
3	2023-01-01	2023-04-01	2
3	2023-01-01	2023-07-01	3

Here's an example SQL Fiddle