Parameters in Power BI are dynamic values that allow you to create flexible and reusable reports by enabling users to change input values that affect queries, calculations, and data connections. They serve as placeholders that can be modified to alter how data is loaded or displayed.
To create a pā¦Parameters in Power BI are dynamic values that allow you to create flexible and reusable reports by enabling users to change input values that affect queries, calculations, and data connections. They serve as placeholders that can be modified to alter how data is loaded or displayed.
To create a parameter, open Power Query Editor by clicking Transform Data from the Home tab. Navigate to Manage Parameters and select New Parameter. You will need to provide a name, description, type (such as Text, Decimal Number, True/False, or Date), and specify whether it allows a list of values, any value, or a single value. You can also set current and default values.
Parameters are particularly useful in several scenarios. First, they enable dynamic data source connections, allowing you to switch between development and production databases by changing a server name parameter. Second, they support incremental refresh by defining date ranges for data loading. Third, they allow end users to filter data through What-if scenarios.
To modify an existing parameter, return to Manage Parameters in Power Query Editor. Select the parameter you wish to edit and adjust its properties such as name, data type, suggested values, or current value. Click OK to save changes, then refresh your data to apply the modifications.
Parameters can be referenced in M queries using the parameter name. For example, in a data source connection string, you might use a parameter like Source = Sql.Database(ServerParameter, DatabaseParameter) to dynamically connect to different servers.
You can also create query parameters from existing columns by right-clicking a column value and selecting Add as New Query, then converting it to a parameter. This approach helps when you want to base parameter values on actual data within your dataset.
Remember to publish your report to Power BI Service where parameters can be configured in dataset settings for scheduled refresh operations.
Create and Modify Parameters in Power BI
Why Parameters Are Important
Parameters in Power BI are essential tools that enable dynamic and flexible data models. They allow you to create reusable queries, make data sources configurable, and enable end-users to filter data based on specific values. Parameters reduce the need for hardcoding values, making your reports more maintainable and adaptable to changing business requirements.
What Are Parameters?
Parameters are named values that can be used throughout your Power BI solution. They act as placeholders that can be referenced in queries, data source connections, and transformations. There are two main types:
Query Parameters: Used within Power Query to filter data, connect to different data sources, or modify query logic.
What-if Parameters: Created in the modeling view to allow users to perform scenario analysis and see how different values affect calculations.
How Parameters Work
In Power Query Editor, you create parameters by navigating to Home > Manage Parameters > New Parameter. When creating a parameter, you define:
- Name: A descriptive identifier - Type: Text, Decimal Number, Date, True/False, etc. - Suggested Values: Any value, List of values, or Query - Current Value: The default value used
Once created, parameters can be referenced in queries using the syntax: ParameterName. You can use them in filter steps, data source paths, or custom M code functions.
Common Use Cases
1. Dynamic Data Source Connections: Switch between development, test, and production servers 2. Date Range Filtering: Allow users to specify start and end dates for data extraction 3. File Path Management: Reference folder locations that may change between environments 4. Threshold Values: Set configurable limits for filtering or conditional logic
Modifying Parameters
To modify existing parameters, go to Home > Manage Parameters in Power Query Editor. You can change the current value, update the allowed values list, or modify the data type. Changes to parameter values refresh all queries that reference them.
Exam Tips: Answering Questions on Create and Modify Parameters
1. Know the difference between query parameters and what-if parameters: Query parameters work in Power Query during data preparation, while what-if parameters work in the report for DAX calculations.
2. Remember the creation path: Parameters are created in Power Query Editor through Manage Parameters, not in the main Power BI Desktop interface.
3. Understand data type implications: The parameter type must match how it will be used. A file path requires Text type, while a filter value might need Decimal Number.
4. Focus on scenarios: Exam questions often present business scenarios requiring environment switching or dynamic filtering. Think about which parameter configuration best solves the problem.
5. Know M code basics: You may see questions about referencing parameters in M code. Parameters are called by their name and require proper syntax.
6. Consider suggested values: When a question mentions restricting user input, think about using List of values or Query for the suggested values setting.
7. Watch for keywords: Terms like 'reusable,' 'configurable,' 'dynamic,' or 'environment-specific' often indicate parameter-related solutions.
8. Practice creating parameters: Hands-on experience helps you recognize correct menu paths and configuration options in scenario-based questions.