In Power BI, parameters are a way to dynamically change the values in your queries and data models. They allow you to create more flexible and interactive reports and dashboards. Here's an overview of parameters in Power BI:
1. **What is a Parameter?**: A parameter is a user-defined input that can be used to modify various aspects of your Power BI report or dataset, such as data source connection details, filter conditions, custom calculations, and more.
2. **Types of Parameters**:
**Query Parameters**: These are used to dynamically modify query parameters like database connections, filtering conditions, or custom query logic.
**Data Model Parameters**: These are used to create dynamic measures, calculated columns, or calculated tables based on user inputs.
3. **How to Create Parameters**:
**Query Parameters**: You can create query parameters by going to Power Query Editor, selecting a query, and choosing "Manage Parameters." Here, you define the parameter type (e.g., text, number, date) and provide a default value.
**Data Model Parameters**: You can create data model parameters by going to the Modeling tab in Power BI Desktop and selecting "New Parameter." Here, you define the parameter's properties and values.
4. **Parameterization Scenarios**:
**Dynamic Data Sources**: You can use parameters to change database connection details (e.g., server names, database names) dynamically.
**Date Range Selection**: Parameters can be used to create date range filters that allow users to select a specific period for analysis.
**What-If Analysis**: Parameters can be used in scenarios where you want users to input specific values to see how they affect calculations and visualizations (e.g., forecasting).
**Multi-Tenant Reports**: In multi-tenant environments, you can use parameters to filter data for different tenants or clients.
5. **Using Parameters in Calculations**: You can reference parameters in DAX formulas and M code, allowing you to create dynamic measures, calculated columns, or custom transformations based on user input.
6. **Parameter Actions**: You can create parameter actions in Power BI to enable user interactions. For example, you can set up buttons or slicers that trigger parameter changes and, consequently, affect your report's visuals.
7. **Data Refresh**: When a parameter is used in a query, changing its value can trigger a data refresh to fetch updated data based on the new parameter values.
8. **Publishing and Sharing**: Parameters are published with your Power BI report or dataset, so users can interact with them in Power BI Service. You can also define parameter descriptions to provide guidance to report consumers.
Power BI parameters provide flexibility and interactivity in your reports, allowing users to customize their experience and perform ad-hoc analyses. They are especially useful when dealing with scenarios where you need dynamic filtering, connection switching, or user-driven calculations.
23 окт 2024
