Incremental Refresh Power BI

[lorenzoglima]

Well, I'm doing a project in Power BI, having been asked to do an incremental refresh of the latest data, without a delimited time, but the data that is not in the Power BI Table was fetched and thus incremented in the table.

I tried to do this through the Power BI' own resource, and realized that this way it could not be done, just delimiting a time for data search, 15 days before, for example. So I'm trying to do this via SQL.

Then the problem starts, even if I try to do this incremental update, the new data is loaded but the previous ones are lost, or erased. I think it's possible to do functions like UPDATE, INSERT AND DELETE, but I'm having some problems. Can someone help me? I can go into more details, if this become necessary.

[V-lianl-msft · Accepted solution]

Power BI is a "read only" system so it doesn't have the ability to store data beyond a refresh. 

You will either have to modify the source system (you said not an option), or put in an intermediate process in place to store a previous day snapshot of data.

See if the blog will help you:

https://visualbi.com/blogs/microsoft/powerbi/historical-data-preservation-using-power-bi-dataflow/ 

[lbendlin]

@lorenzoglima To do incremental refresh in Power BI you must have a suitable DateTime column either in your data itself (for example "Order Date") or in the source files (in case you receive daily CSV files with the data).  If your column is not in DateTime then you must convert it.  For example if all you have is a date then you need to pick a time (usually midnight).

for example: From "2021-08-20" to "2021-08-20T00:00:00.0" 

Once you have that you can proceed to create your parameters (RangeStart and RangeEnd) and apply them as filter to your data source etc.