Table of Contents

Function and set properties

  • 2026-10-05
  • Jeroen ter Heerdt
Applies to:
  • ⚠ Tabular Editor 2 Supports functions and sets, but not Namespace, PackageId or PackageVersion
  • Tabular Editor 3 (Available since 3.23.0)
    ✔ Desktop
    ✔ Business
    ✔ Enterprise
Note

This page was created with the help of AI.

This page lists the properties of DAX user-defined functions and of sets. For properties that most objects share, see Common properties.

Function

A User-Defined Function (UDF) is a reusable DAX function that you define once in the model and call from any DAX expression, including other functions. It takes parameters, which can be values, tables or references to columns and measures, and returns a value or a table. UDFs belong to the model, and the TOM Explorer lists them under the Functions folder.

UDFs need compatibility level 1702 or higher. Azure Analysis Services and SQL Server Analysis Services don't support them. For a full introduction, see DAX User-Defined Functions.

Tabular Editor 2 also supports UDFs and lists them under the Functions folder. To add one in Tabular Editor 2, right-click the folder and choose New User-Defined Function. Tabular Editor 2 doesn't have the Namespace, PackageId and PackageVersion properties.

Common properties

You call a function by its name in DAX, so the name can't contain spaces. It can contain periods and underscores. Use a compound name such as Finance.Margin or ACME_Margin to avoid a clash with a built-in DAX function that Microsoft adds later. See Use Compound Names for User-Defined Functions. When you rename a function, Tabular Editor 3 updates the references to it throughout the model, as Formula Fix-up and Formula Dependencies does for measures and columns.

Namespace

Namespace · string · Basic · stored as an annotation (TE_Group)

The group that the function appears under in the TOM Explorer view when grouping of user-defined functions by namespace is on. Turn the grouping on with the toggle button above the TOM Explorer. Tabular Editor determines the namespace in this order:

  1. if the function has a TE_Group annotation, that's the namespace
  2. otherwise, if the function's name contains a dot, the namespace is the part before the last dot, so DaxLib.Convert.CelsiusToFahrenheit is in namespace DaxLib.Convert
  3. otherwise, if the function has a DAXLIB_PackageId annotation (see PackageId), the namespace is the package ID
  4. otherwise, the namespace is empty

You can set a different namespace without renaming the function. Tabular Editor stores it in the TE_Group annotation on the function, which is saved with the model. To go back to the namespace from the name, reset the property or clear the value. Like a display folder, the namespace only organizes the TOM Explorer, and in DAX you always call the function by its full name.

For example, if you batch rename a set of functions to remove the DaxLib.Convert. prefix from their names, set their namespace to DaxLib.Convert to keep them grouped.

PackageId

PackageId · string · Metadata · read-only · stored as an annotation (DAXLIB_PackageId)

The ID of the DaxLib package that the function comes from, read from the function's DAXLIB_PackageId annotation. DaxLib packages put this annotation on their functions. The Properties view only shows PackageId and PackageVersion when the function has this annotation, so functions that you wrote yourself don't show them.

The DAX Package Manager in Tabular Editor 3 removes the DAXLIB_ annotations when it installs a function and tracks the package with extended properties, described under PackageVersion. You see these properties on functions from a DaxLib package that were added to the model without the DAX Package Manager. See DAX Package Manager.

PackageVersion

PackageVersion · string · Metadata · read-only · stored as an annotation (DAXLIB_PackageVersion)

The version of the DaxLib package that the function comes from, read from the function's DAXLIB_PackageVersion annotation.

The DAX Package Manager doesn't use PackageId and PackageVersion. It tracks installed packages in extended properties. On the model, TabularEditor_ModelDaxPkgTable and TabularEditor_ModelDaxPkgSeq list the installed packages. On each function, TabularEditor_ObjDaxPkgHandle records which package the function belongs to and TabularEditor_ObjDaxPkgContentHash records what its expression looked like when it was installed. If you change the expression of a function that came from a package, a prompt appears when you later update or remove the package, asking what to do with the changed function.

To stop the DAX Package Manager from tracking a function, remove both its TabularEditor_ObjDaxPkgHandle and TabularEditor_ObjDaxPkgContentHash extended properties. Removing the package then no longer deletes the function, and the package still shows as installed. If you later update or reinstall the package, a prompt appears for the conflict with the existing function of the same name. If you remove only TabularEditor_ObjDaxPkgContentHash, the function counts as changed and every update prompts about it. The DAX Package Manager documentation warns that changing these extended properties by hand can lead to unexpected behavior.

Expression

Expression · string · Options

The function's parameter list and body in lambda notation: the parameters in parentheses, then =>, then the DAX expression that uses them. For example:

// Returns the relative change between two values
(
    oldValue: NUMERIC,  // The original value
    newValue: NUMERIC   // The value to compare against
)
=> DIVIDE ( newValue - oldValue, oldValue )

Each parameter can have a type, such as NUMERIC, STRING or TABLE, and an evaluation mode. VAL, the default, evaluates the argument once before the function runs, like a variable. EXPR passes the expression itself, which is evaluated in the context where the function uses it, like a measure. A parameter followed by = expression is optional. See DAX User-Defined Functions for the full syntax.

Tabular Editor 3 shows the comments in the expression in autocomplete suggestions and tooltips when you call the function.

In Tabular Editor 3, you can edit functions together with other objects in a DAX Scripts document, with the FUNCTION keyword. You can also write a function in the DEFINE section of a DAX Queries and apply the query to add the function to the model.

Set

A set belongs to a table and holds a DAX expression. The Tabular Object Model (TOM) describes it as a calculated set. Sets are only supported in Power BI and Fabric models, at compatibility level 1400 or higher. In a model in Analysis Services compatibility mode, the TOM library rejects a new set with the error "is not supported at AnalysisServices mode".

Sets don't appear in the TOM Explorer. To add, edit or remove the sets of a table, select the table and click the ... button of its Sets property (see @object-properties-tables). The Properties view only shows that property for models in Power BI compatibility mode at compatibility level 1400 or higher.

Common properties

Expression

Expression · string · Options

The DAX expression that defines the set.

Dynamic

IsDynamic · bool · Options

Whether the set is static or dynamic. A static set is evaluated once, and its members don't change with the filters in a query. A dynamic set is evaluated for each query, in the context of that query, and its members can change with the filters.