Final answer:
Before generating a Power BI report to display the count of items sold by each store, one should perform data modeling, establish proper relationships in the Power Pivot model, and create a DAX measure for the count of items sold.
Step-by-step explanation:
The correct answer is that before creating the report in Power BI to display the count of items sold by each store, you should perform a data modeling task. Specifically, you need to ensure that your data is shaped correctly for the report. This may include setting up relationships between tables within the Power Pivot model if they're not already established. Additionally, you will likely need to create a calculated column or a measure to count the number of items sold. The most common way to do this in Power BI is by using Data Analysis Expressions (DAX) to define a measure that counts the rows in a table or counts the number of a specific value within a column. Once your data model is properly configured, you can use Power BI's visualization tools to generate the report and present the count of items sold by each store.
By creating relationships between tables, you establish the connection between them based on their common fields. This enables Power BI to aggregate and analyze data across multiple tables accurately. In this case, you would need to create a relationship between the table containing sales data and the table containing information about each store.
Once the relationships are established, you can use the power of Power BI to generate a report that displays the count of items sold by each store, leveraging the connected tables and their relevant fields.