Data for this day last year?

[gmlhawkins]

I have a csv data source that is just really a log file. Each row contains a date and then the totals from another system in various other columns (Date, Total Hours, Total Students,) etc. The file is written each day in the early morning. I have been successful in showing data just for today but I would like to also show data from this day, last year. I am relatively new to this and cannot figure it out. 

[AlexChen]

Hi,

I assure the table you imported from CSV looks like below.

You can create a calculated column to get last year sam day’s value.

lastYearTotals = var

             lastYear = DATEADD(logInfo[date], -1, year)

         return

             LOOKUPVALUE(logInfo[totals], logInfo[date], lastYear)

This is the result:

Best Regards

Alex

[GilesWalker]

@gmlhawkins There are a couple ways this can be done. Firstly you will need to create a date table, see the post below where I spoke about this:

http://community.powerbi.com/t5/Desktop/Noob-Date-question/m-p/38881#

Once you have this date table you then create a relationship to the CSV file you have through the date column. Then you can use DAX formulas such as SAMEPERIODLASTYEAR

Are the CSV files you get always in the same format, i.e. the columns are always the same? If so then you can keep them all in one folder and use the get data / folder option in Power BI desktop and this will join them all together.

Thanks,

Giles