check if data is for previous month

Question

hello,
in data flow I would like to make sure the data is for previous month only
my concern is what if we are in jan 2023, will this filter for Dec 2022 as well?
This is what I am doing in two separate filters

last month data:
step1--> filter in dataflow for year
equals(year(toDate(dateColumnName,'yyyyMMdd')),year(currentUTC()))

step2--> filter in dataflow for last month
equals(month(toDate(dateColumnName,'yyyyMMdd')), month(addMonths(toDate($p_CurrentDate, 'yyyy-MM-dd'),-1)))

thank you

Answer 1

Hello @arkiboys ,

Thanks for the question and using MS Q&A platform.

If check or make sure if the date column is from previous month or not you can use below expression in dataflow expression builder.

equals(subMonths(lastDayOfMonth(currentDate()),1), lastDayOfMonth(toDate(dateColumnName,'yyyy-MM-dd')))  

You can use combination of lastDayOfMonth() and subMonths() functions to achieve your requirement and this will calculate the correct Month difference even there is a change in year same as yours (for Example Current month is Jan 2023 and the dateColumn Month is Dec 2022). These functions will take care of it automatically. You can avoid the extra step to verify the year difference.

Sample demonstration below:

Hope this will help. Please let us know if any further queries.

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