Ok, I don’t want to make it a long post, so here’s the thing: one of the Data Profiling feature is “Column distribution”.
Column Distribution allows you to get a sense for the overall distribution of values within a column in your data previews, including the count of distinct values (total number of different values found in a given column) and unique values (total number of values that only appear once in a given column).
So, distinct and/or unique. For anyone else these 2 words may seem similar, but for Data Guys like us, these are 2 different things (just like empty and null 🙂 ). Still confused? Here’s a very simple example to clear things up:
Let’s say we have a small company with 10 employees using 10 laptops from different Manufacturers: HP, Dell, Apple and Lenovo.
Distinct: We have laptops from 4 different Manufacturers (HP, Dell, Apple and Lenovo) aka “total number of different values”, regardless of how many of each we have. Unique: We have only 2 laptops that nobody else have in our company (one from Apple and another one from Lenovo) aka “total number of values that only appear once”.
Thinking legacy, here’s the same thing in Excel, using countif or countifs.
Read his blog post to see how he reached to below conclusion:
DateAdd and SamePeriodLastYear both work based on the DYNAMIC period in the filter context.
ParallelPeriod is working STATICALLY based on the interval selected in the parameter.
ParallelPeriod and DateAdd can go more than one interval back and forward, while SamePeriodLastYear only goes one year back.
DateAdd works on the interval of DAY, as well as month, quarter and year, but ParallelPeriod only works on month, quarter, and year.
Depends on the filter context you may get a different result from these functions. If you get the same result in a year level context, it doesn’t mean that all these functions are the same! Look more into the detailed context.
Refreshing Power BI report generates “The key didn’t match any rows in the table” error.
Click “Edit Queries” button. If you do not see the error message, click “Refresh Preview” button. Once you have the error message, click “Go To Error“.
Error message will remain, but you should have “Edit Settings” button now, click it.
In the next screen, Navigation, you should see what exactly Power BI is trying to access but cannot do so.
In my example, I have an Excel file as my source. When I first connected to this data source, my Table name was Table1. Yesterday I changed where my Excel file gets data from and this, in turn, changed Excel’s Table name to “report“.
Obviously, when Power BI tries to refresh the data, it cannot find Table1 table anymore.
In the same Navigation screen, selecting my new Table name “report” will fix the issue assuming all other columns in the Excel file are the same.
Same is true for any data source, not only Excel file. Follow same steps to identify what’s causing the error and then fix it as needed.