M Query Guide

Basics

M Security Basics

M Security Practices

M security ensures safe data handling in Power Query.

Introduction to M Security

In Power Query, the M language is used to perform data transformations. However, these transformations need to be executed with security in mind to prevent unauthorized data access and manipulation. Understanding and implementing M security features is crucial for ensuring safe data handling.

Understanding M's Security Contexts

M operates within various security contexts that determine how data is accessed and processed. These contexts are:

  • User context: The operations performed by a user with their permissions.
  • Service context: Operations performed by the Power BI service with its permissions.

Knowing which context is being used helps in auditing and ensuring compliance with data protection policies.

Data Privacy Levels

Data privacy levels in M play a significant role in controlling data access. These levels include:

  • Private: Data sources that contain sensitive information that shouldn't be combined with other data sources.
  • Organizational: Data sources that can be combined with other organizational data but not public data.
  • Public: Data sources that can be freely combined with other data sources.

Setting appropriate privacy levels helps prevent unintended data exposure.

Implementing Privacy Levels in Power Query

When working with data in Power Query, it's essential to set the privacy level for each source to ensure data is handled correctly.

In this example, a CSV file is read into Power Query, and a privacy level of Private is assigned to ensure that sensitive data is handled securely.

Best Practices for M Security

To enhance the security of your M scripts, consider the following best practices:

  • Always define the privacy levels for all data sources.
  • Limit the use of custom connectors, ensuring they are from trusted sources.
  • Regularly review and update data access permissions in Power BI.
  • Use parameterized queries to prevent injection attacks.

By following these practices, you can enhance the security and integrity of your data processing activities in Power Query.

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