# Struct Mask This is a [composite generator](https://docs.tonic.ai/app/generation/generators/generator-types/generators-composite). Applies selected generators to specific StructFields within a StructType in a Databricks database. For example, for the following StructType: ``` root |-- firstname: string (nullable = true) |-- lastname: string (nullable = true) |-- age: integer (nullable = true) |-- occupation: string (nullable = true) |-- salary: integer (nullable = true) firstname | lastname | age | occupation | salary ------------------------------------------------- John | Smith | 25 | Teacher | 45000 ``` To get the value of the `occupation` field, you would use the expression `root.occupation`. ## Characteristics


Consistency	Determined by the selected sub-generators.
Linking	Determined by the selected sub-generators.
Differential privacy	Determined by the selected sub-generators.
Data-free	Determined by the selected sub-generators.
Allowed for primary keys	No
Allowed for unique columns	No
Uses format-preserving encryption (FPE)	No
Privacy ranking	5
Generator ID (for the API)	`StructMaskGenerator`

## How to configure ### Adding a sub-generator To assign a generator to a path expression: 1. Under **Sub-generators**, click **Add Generator**.\ \ On the sub-generator configuration panel, the **Cell Struct** field contains a sample value from the source database. You can use the previous and next icons to page through different values. 2. In the **Path Expression** field, type the path expression to identify the value to apply the generator to.\ \ **Matched Struct Values** shows the result from the value in **Cell Struct**. 3. From the **Generator Configuration** dropdown list, select the generator to apply to the path expression.\ \ You cannot select another composite generator. 4. Configure the selected generator.\ \ You cannot configure the selected generator to be consistent with another column. 5. To save the configuration and close the add generator panel, click **Save**. ### Managing sub-generators From the **Sub-Generators** list: * To edit a generator assignment, click the edit icon. * To remove a generator assignment, click the delete icon. * To move a generator assignment up or down in the list, click the up or down arrow.