How to Say “Is Not Null” in Tableau

Tableau is a powerful data visualization tool that helps analysts and data scientists gain insights from their data. When working with data, it’s common to filter out or exclude null values, which are essentially missing or unknown data points. In Tableau, the equivalent of saying “is not null” is to use a combination of operators and functions to achieve the desired result.

Using the “Is Not Null” Operator in Tableau

Tableau provides a straightforward way to express “is not null” using the “Not Null” operator. This operator is especially useful when you want to filter your data based on the absence of null values. Here’s how you can use it in Tableau:

1. Select the field to which you want to apply the “is not null” condition.
2. Right-click on the field and choose “Filter”.
3. In the filter dialog box, select the “Condition” tab.
4. From the dropdown menu, choose “Not Null.”
5. Click the “OK” button to apply the filter.

This simple approach allows you to exclude any null values from your analysis, refining your data set to only include valid and known data points.

Alternative Methods to Express “Is Not Null”

If you prefer using Tableau’s calculation features, you can also express “is not null” using calculated fields. Here are a few alternative methods:

Method 1: Using IFNULL()

The IFNULL() function in Tableau returns a specified value if an expression evaluates to null; otherwise, it returns the expression itself. In the case of filtering out null values, you can create a calculated field using IFNULL() as follows:

Step 1: Right-click on the Data pane and choose “Create Calculated Field”.

Step 2: In the calculation editor, enter the following formula:

IFNULL([Your Field], “NotNull”)

Replace “[Your Field]” with the actual field you want to filter.

Step 3: Click the “OK” button to save the calculated field.

Step 4: Drag the calculated field to the Filters shelf, and choose “NotNull” from the filter options.

This method provides an alternative way to express “is not null” using a calculated field and the IFNULL() function.

Method 2: Using ISNULL()

Similar to IFNULL(), the ISNULL() function in Tableau allows you to check if a field’s value is null. Using ISNULL() in a calculated field, you can express “is not null” like this:

Step 1: Right-click on the Data pane and choose “Create Calculated Field”.

Step 2: In the calculation editor, enter the following formula:

ISNULL([Your Field]) = False

Replace “[Your Field]” with the actual field you want to filter.

Step 3: Click the “OK” button to save the calculated field.

Step 4: Drag the calculated field to the Filters shelf and select “True”.

This method utilizes the ISNULL() function in a calculated field to filter out rows with null values.

Additional Tips and Examples

Here are a few tips and examples to help you understand and use the “is not null” concept in Tableau:

1. Use “is not null” with multiple fields: You can apply the “is not null” condition to multiple fields simultaneously. Tableau will filter out rows where any of the selected fields have null values.
2. Combining filter conditions: You can combine the “is not null” filter condition with other logical operators, such as “and” or “or”, to create more complex filter conditions.
3. Aggregation and “is not null”: When working with aggregated data, you might encounter situations where “is not null” does not yield the expected results. In these cases, consider applying the filter before or after aggregation, based on your specific requirements.

Let’s look at an example where we have a dataset containing customer information, including names and ages. To filter out customers with missing age information, we can apply the “is not null” condition to the age field:

Step 1: Select the age field and right-click to open the filter dialog.

Step 2: Choose the “Condition” tab and select “Not Null” from the dropdown menu.

Step 3: Click “OK” to apply the filter.

Once the filter is applied, Tableau will only display customer records where the age field is not null, allowing you to analyze the available data more effectively.

In Conclusion

Understanding how to express “is not null” is crucial in Tableau when you want to filter or exclude missing or unknown data from your analysis. Tableau provides several methods to achieve this, such as using the “Not Null” operator or creating calculated fields using functions like IFNULL() or ISNULL(). By implementing these techniques, you can ensure your analysis is based on valid and complete data, leading to more accurate insights.

Remember to experiment with different methods and explore Tableau’s documentation for further insights and examples. Happy analyzing!