Concept: Prism Calculated Fields
A Prism calculated field is a user-created field that generates its values based on a calculation or condition, and returns a value for each input row. Values are computed based on expressions that can contain values from other fields, constants, mathematical operators, comparison operators, or built-in row functions.
Use Prism calculated fields to:
- Derive meaningful values from base fields, such as calculating someone's age based on their birthday.
- Do data cleansing, such as substituting 1 value for another.
- Compute new data values based on a number of input variables, such as calculating a profit margin value based on revenue and costs.
Sometimes you need several steps to achieve the result that you want. You can use the result of a Prism calculated field in the expressions of other Prism calculated fields, enabling you to define a chain of processing steps.
When you create a Prism calculated field, the inspector panel displays for the new field. To see a list of available functions, click the
Functions Library
tab in the inspector panel.You can extract and export the expressions used in dataset pipelines as CSV files from the
View Dataset Lineage
report. Calculated Field Deletion
You can delete reports or calculated fields within reports without deleting any existing calculated field references in Prism. When you delete a report or a calculated field, you’ll receive a warning to caution you that the Prism pipelines referring to a particular calculated field will break if there are any existing references. The warning message also directs you to the
View Calculated Field Usage in Prism
task that displays all current Prism references to a calculated field.To avoid downstream issues in your Prism pipelines, we recommend that you use the
View Calculated Field Usage in Prism
task to find and remove all existing references in Prism before deleting a report or calculated field in a report.