I follow the following blog http://sqljason.com/2018/03/display-last-n-months-selected-month-using-single-date-dimension-in-powe... in order to display Display Last N Months & Selected Month using Single Date Dimension in Power BI.
I've an issue when trying to display month-year when there is no data in the fact table sales.
I did modification: https://1drv.ms/u/s!Amd7BXzYs7AVg3xJ1MKPYI_PIw3z
How to show to show for example October, november and december 2015 as an example?
I downloaded your PBIX file and looked through it.
I am unsure what you exactly want to see, because your report has a few quirks in it.
I'll try to sum them up:
You have a 'select month' drop down menu ánd a slider for selecting the number of months (As 'sales for last x months). This doesn't work. Since you now need to manually select the wanted months in the drop down menu with CTRL+Click (On each month) ánd you need to use the slider.
Next to that, your calculations seem to be wrong. If I only select Dec-16 I get 70. If I select Nov-16 and Dec-16, the sales in Dec-16 suddenly become 70 and Nov-16 takes over. If I select until July-16, July-16 gets 70 and Dec-16 gets 120.. I don't know if this is how you want it but it looks like strange behaviour.
A good tip for measures. If you sum, divide or do any calculation. End with +0. That way you wont see (Blank) but 0. E.g.
Sales (Selected Month) = SUM(Sales[Sales]) + 0
Also, you have made a small date table, which is good. But you don't use this consistently through your report. For selecting months you use the date table and for the graph you use the date in the sales table. It is better to use the date table for dates, since that is it's sole purpose.
Link: https://learn.microsoft.com/en-us/power-bi/admin/service-premium-incremental-refresh
It is mentioned that: "An update is interpreted as an insertion and a deletion, not an actual update."
If store rows in last 1 year is configured. And refresh rows in last 7 days is configured. Then if particular OrderDate value is modified (within last 7 day), then will it insert a new record and delete the old record?
If prior to 7 day is modified then how is it handled?
Similarly if the row from last 7 days is deleted or the row prior to last 7 days is deleted then how does incremental refresh handle this?
For example, if i have
The after refresh
As you see, powerbi split my Data into partition:
1 whole Year (2019)
3 whole Quarter (from 2020)
3 whole Month (2020Q410 - 2020Q412)
I have set the refresh for 1 month, so on subsequent starts it will only load data for the current month - 2020Q412.
AD1) I this case, powerbi remove ALL data from partition and insert ALL (not only new rows from your source or updated rows)
AD2) Power BI do nothing, because change is outside declared range
I just want to select a range of days in a slicer and show in a table the number of days for each month/period (month-year).
I used DAX to create a table with the information I need and I don't have problems with the periods (first column), it changes dinamically, the problem is the column "Days" (second column) because it's always showing the total number of days for each month.
Here my DAX code
SelectedPeriods = GROUPBY(DimDate;DimDate[Period];"Days";COUNTX(CURRENTGROUP();DimDate[DateKey]))
Here the result
What I expect is:
2 for april, 31 for may, 1 for june
This is an issue with execution order.
SelectedPeriods = GROUPBY(DimDate;DimDate[Period];"Days";COUNTX(CURRENTGROUP();DimDate[DateKey]))
Generates a calculated table. These are calculated when the data model is refreshed and stored in it. They are not refreshed each time a connected dimension is changed within a dashboard.
In your case, while changing date filters may hide rows from this table the number of days remains fixed at the number calculated initially when there was no filter context on the data i.e. counting all days in the month.
If you want the result to change then you need to use a measure instead of a calculated table. Measures react to the current filter context within the report and so will adjust their output each time a slicer is changed.
The needed measure will depend on your model but might be something as simple as:
CountOfDays := CountRows(DimDate)
I work in an educational department where the start date of our academic calendar changes every year. Some years it might be week 9 of the year, some years it might be week 10. There is no formula used to figure out this start date, it's based a combination of factors and is picked by humans.
I want to be able to compare calls received in week 1 of the academic calendar 2017 to calls received in week 1 of the academic calendar 2018 and 2019.
I am using PowerBI desktop and trying to create a calendar table that includes a column "academic calendar week" or similar.
Does anyone have any suggestions on how to offset start date of the calendar by a different number of weeks for each year?
Need help in Data Analytics Calculations.
Currently, I am getting historical data for consumption as follows:
on above data, I am adding custom columns for calculating exact consumption(gallons) in no. of days. like:
Now, I have to plot month wise bar chart for consumption of respective Meter ID in 2016 year. But problem here is, I will have to calculate Every months consumption by dividing it in days in each respective month of 2016, and then only I will able to plot them monthly like:
y axis = consumption in every month
x axis = Jan Feb March Apr May Jun Jul Aug Sep Oct Nov Dec
so, in jan month, consumption should be = 10 + 100 + ((115/38) * 7) gallons
Notes: here, in ((115/38) * 7) : we are calculating avg consumption of single day 7 days in Jan and whole march and then getting last 7 day consumption of Jan so that we can add it in calculation of total consumption of Jan month
but how to add measure/custom column/new table for these calcualtions?
Thanks
What you need to do is relatively complicated, but the summary of my solution is:
Calculate the per-day consumption
Calculate the start and end date of each reading (e.g. the previous reading date plus one day, and the reading date)
Expand your data to have 1 row per day rather than 1-row per reading
You want to do these steps before you load the data into your data model (i.e. in your source system, or as the data is loaded using the Query Editor/Power Query).
Below, I assume you're using the Query Editor/Power Query. However, if you can use your source system, it's often the better choice (since the source system may be a database that is vastly faster than your desktop).
Note that your No. of Days calculation doesn't make sense to me. There are more than 38 days between 24 Jan 2016 and 31 Mar 2016. There are also more than 13 days between 10 Jan and 24 Jan. For this reason, it was difficult to tell whether you wanted a new reading to count on the day the previous reading was taken, or on the next full day. I assume the former. Also note, I've proceeded on the basis that your No. of Days calculation is correct
Calculate the Per Day Consumption
This is the easiest step, given that you have already calculated the Consumption and the No. of Days. Just divide one by the other. In the Query Editor, you can click in the Consumption (gallons) column and select Add Column > Standard > Divide. Under Value, choose Use values in a column and then select the No. of Days column.
Calculate the Start & End Date of Each Reading
The date of the reading is the end date, so you can rename Date to be End Date (since a reading is applied retroactively).
For the start date, in the Query Editor, you will need to add an index column (Add Column > Index Column). You will want to make sure your data is sorted by Meter ID and Date Ascending before doing this. Call the column Index.
Next, Add Column > Custom Column and pull the reading date from the prior row. Call the new column Previous End Date for now.
// A try is necessary because we can't get the previous row if there is no previous row (we'll get an error, which we can handle in the 'otherwise' block)
try
if
// See if the previous row is for the same Meter ID
[Meter ID] = #"Reordered Columns"{[Index] - 1}[Meter ID]
then
// If it is, grab the Reading Date from the previous row
#"Reordered Columns"{[Index]-1}[End Date]
else
// If this is the first reading for a meter, calculate the Start Date by subtracting the No. of Days from the End Date
Date.AddDays([End Date], -[No. of Days])
otherwise
// If this is the first row in the table, also calculate the Start Date by subtracting the No. of Days from the End Date
Date.AddDays([End Date], -[No. of Days])
Next, you'll want to add 1 to the Start Date, as we want the reading to apply to the day after the previous reading, not on the day of the previous reading.
Note, if you want the reading date to count in the prior period, subtract 1 from the End Date rather than add 1 to the start date (previous end date).
Expand your data to have 1 row per day
At this point, you should have a Meter ID, Start Date, End Date, and per day consumption column that reflects what you expect (i.e. the per day consumption is correct for the date range).
The final step is to duplicate each row for each date in the date range. There are several solutions to this outlined in this thread (https://community.powerbi.com/t5/Desktop/Convert-date-ranges-into-list-of-dates/td-p/129418), but personally, I recommend the technique (and video) posted by MarcelBeug (https://youtu.be/QSXzhb-EwHM).
You should end up with something more like this (after some removing & renaming of columns):
Finally
Now that you have one row per meter & date, with a per day consumption already calculated, you can build a visual. For example, you could do a column chart with Date on the Axis, and Consumption per Day as the value. By default, Power BI will recognize that Date is a date, and will roll it up by Year-Quarter-Month-Day. Press the little 'x' by Year and Quarter, and you'll have a chart that sums up the per day consumption by month. You can also drill down to individual date.
Further Reading
Reading a value from a previous row in Power Query
If Statements in Power Query
The AddDays function in Power Query
Adding Comments in Power Query
Catching Errors in Power Query
Converting a date range into a list of dates (Marcel Beug's solution)
A similar problem I previously answered