Database for creating inside reports

Hi Varik966 ,

Power BI can't be used as the database, as this official documentation referred, Power BI lets you connect the data sources to create the report and share the insights with everyone you want. It includes the following 3 basics:

• A Windows desktop application called Power BI Desktop.
• An online SaaS (Software as a Service) service called the Power BI service.
• Power BI mobile apps for Windows, iOS, and Android devices.

And where the data in the excel file should store? You can just keep them in the excel file, and make filter on the old data which is for X years ago to delete them. Or you can manage these data in the SQL server database, later create a sql command to delete these old data...

Store data in SQL SERVER:

Create database:

CREATE DATABASE & CREATE TABLE Operations

Import data from Excel to SQL Server:

Import data from Excel to SQL Server or Azure SQL Database

Delete the old data:

DELETE

Lastly, you can refer the following link to connect your data to create the report in Power BI Desktop. 

1. If the data source is Excel file

Connect to Excel in Power BI Desktop

2. The data source is SQL Server

Refresh data from an on-premises SQL Server database

Best Regards