MDX Query For Filtering Non Empty Values

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Introduction

When working with Performance Point Dashboards, it's essential to filter out non-empty values to provide accurate and relevant data to users. In this article, we'll explore how to create a filter in Performance Point Dashboard using an MDX query to select only non-empty values.

Understanding MDX Queries

MDX (Multidimensional Expressions) is a query language used to analyze and manipulate data in OLAP (Online Analytical Processing) databases. It's a powerful tool for creating complex queries and calculations. In the context of Performance Point Dashboards, MDX queries are used to retrieve data from OLAP databases and display it in a user-friendly format.

Creating a Filter for Non-Empty Values

To create a filter for non-empty values in Performance Point Dashboard, you'll need to write an MDX query that selects only the non-empty values from the desired dimension. In this example, we'll use the [H School] dimension and select only the non-empty values from the [Dist Name] and [... attributes.

MDX Query for Non-Empty Values

SELECT NONEMPTY{[H School].[Dist Name], [H School].[...]} ON COLUMNS
FROM [Cube Name]

In this query, NONEMPTY is a function that returns only the non-empty values from the specified dimension. The {[H School].[Dist Name], [H School].[...]} syntax specifies the dimension and attributes to be filtered. The ON COLUMNS clause specifies the columns to be displayed in the result set.

Breaking Down the MDX Query

Let's break down the MDX query to understand how it works:

  • SELECT: This keyword begins the MDX query.
  • NONEMPTY: This function returns only the non-empty values from the specified dimension.
  • {[H School].[Dist Name], [H School].[...]}: This syntax specifies the dimension and attributes to be filtered. In this case, we're filtering the [Dist Name] and [...] attributes from the [H School] dimension.
  • ON COLUMNS: This clause specifies the columns to be displayed in the result set.
  • FROM [Cube Name]: This clause specifies the OLAP cube to be queried.

Tips and Variations

Here are some tips and variations to keep in mind when working with MDX queries:

  • Use the NONEMPTY function: The NONEMPTY function is a powerful tool for filtering out non-empty values. Use it to simplify your queries and improve performance.
  • Specify the dimension and attributes: Make sure to specify the dimension and attributes to be filtered using the {} syntax.
  • Use the ON COLUMNS clause: The ON COLUMNS clause is used to specify the columns to be displayed in the result set.
  • Test your query: Always test your query to ensure it returns the expected results.

Common MDX Functions for Filtering Non-Empty Values

Here are some common MDX functions for filtering non-empty values:

  • NONEMPTY: Returns only the non-empty values from the specified dimension.
  • FILTER: Returns a subset of rows from the specified table or query.
  • EXISTING: Returns only the existing values from the specified dimension.

Example Use Cases

Here are some example use cases for the MDX query:

  • Filtering non-empty values: Use the MDX query to filter out non-empty values from a dimension, such as [H School].[Dist Name].
  • Creating a dashboard filter: Use the MDX query to create a filter in Performance Point Dashboard that selects only non-empty values from a dimension.
  • Analyzing data: Use the MDX query to analyze data in an OLAP cube and identify trends and patterns.

Conclusion

Introduction

In our previous article, we explored how to create a filter in Performance Point Dashboard using an MDX query to select only non-empty values. In this article, we'll answer some frequently asked questions (FAQs) about MDX queries and filtering non-empty values.

Q: What is the difference between NONEMPTY and FILTER functions in MDX?

A: The NONEMPTY function returns only the non-empty values from the specified dimension, while the FILTER function returns a subset of rows from the specified table or query. While both functions can be used to filter out non-empty values, NONEMPTY is generally more efficient and easier to use.

Q: How do I specify the dimension and attributes to be filtered in an MDX query?

A: To specify the dimension and attributes to be filtered, use the {} syntax. For example: {[H School].[Dist Name], [H School].[...]}. This syntax specifies the dimension and attributes to be filtered.

Q: What is the ON COLUMNS clause in an MDX query?

A: The ON COLUMNS clause specifies the columns to be displayed in the result set. This clause is used to define the layout of the result set.

Q: Can I use the NONEMPTY function with other MDX functions?

A: Yes, you can use the NONEMPTY function with other MDX functions, such as FILTER and EXISTING. For example: NONEMPTY(FILTER([H School].[Dist Name], [H School].[...])).

Q: How do I troubleshoot an MDX query that is not returning the expected results?

A: To troubleshoot an MDX query, try the following:

  • Check the syntax of the query for errors.
  • Verify that the dimension and attributes are correctly specified.
  • Test the query with a small subset of data to ensure it is working as expected.
  • Use the DEBUG function to step through the query and identify the source of the issue.

Q: Can I use MDX queries in other tools and applications?

A: Yes, MDX queries can be used in other tools and applications, such as:

  • SQL Server Analysis Services (SSAS)
  • SQL Server Reporting Services (SSRS)
  • Power BI
  • Excel

Q: What are some common mistakes to avoid when writing MDX queries?

A: Some common mistakes to avoid when writing MDX queries include:

  • Incorrect syntax
  • Missing or incorrect dimension and attribute specifications
  • Failure to specify the ON COLUMNS clause
  • Using the wrong MDX functions or syntax

Q: How do I optimize an MDX query for performance?

A: To optimize an MDX query for performance, try the following:

  • Use the NONEMPTY function to reduce the amount of data being processed.
  • Use the FILTER function to reduce the amount of data being processed.
  • Use the EXISTING function to reduce the amount of data being processed.
  • Use the DEBUG function to step through the query and identify performance bottlenecks.

Conclusion

In this article, we've answered some frequently asked questions about MDX queries and filtering non-empty values. We've discussed the NONEMPTY function, specified the dimension and attributes, and used the ON COLUMNS clause to display the result set. We've also provided tips and variations, as well as common MDX functions for filtering non-empty values. With this knowledge, you can create powerful filters and analyses in Performance Point Dashboard.