> ## Documentation Index > Fetch the complete documentation index at: https://docs.activeviam.com/llms.txt > Use this file to discover all available pages before exploring further. # Override default managed objects > How to override the default database entity classes in Atoti Sign-Off to modify field lengths, add columns, change converters, or apply Hibernate filters to managed objects. ## Overview Atoti Sign-Off provides several objects out-of-the-box that are managed by the default `EntityManager`. Each of these objects is defined as a JPA entity using the `@Entity` and `@Table` annotations. The default entity classes are: | Managed Object | Entity Class | | ----------------------------- | --------------------------------------------------------------------------------------------- | | SignOff Process Definitions | `com.activeviam.signoff.workflow.model.definition.jpa.SignOffProcessDefinitionEntity` | | SignOff Process Instances | `com.activeviam.signoff.workflow.model.instance.jpa.SignOffProcessInstanceEntity` | | Adjustment Definitions | `com.activeviam.signoff.workflow.model.adjustment.definition.jpa.AdjustmentsDefinitionEntity` | | Adjustment Executions | `com.activeviam.signoff.workflow.history.jpa.AdjustmentExecutionEntity` | | Adjustment Definition History | `com.activeviam.signoff.workflow.history.jpa.AdjustmentDefinitionHistoryEntity` | | Adjustment Execution History | `com.activeviam.signoff.workflow.history.jpa.AdjustmentExecutionHistoryEntity` | However, many of the default entity classes inherit fields from a parent class that is annotated with `@MappedSuperclass`. If you wish to modify a field inherited by one of the default entity classes, you need to override the parent class where that field is defined instead of the entity class. Be cautious when doing this, as any other entity classes inheriting from the same parent class will also be affected. The default `@MappedSuperclass` classes are: | Mapped Superclass | Inheriting Entity classes | | ---------------------------- | ------------------------------------------------------------------------------------ | | Workflow Process Definitions | `com.activeviam.workflow.core.model.definition.jpa.AWorkflowProcessDefinitionEntity` | | Process Instances | `com.activeviam.workflow.core.model.instance.jpa.AProcessInstanceEntity` | | History Records | `com.activeviam.workflow.core.workflow.history.jpa.AHistoryRecordEntity` | In some scenarios, you may want to override the default managed objects, for example: * to change the length of a database [column](https://jakarta.ee/specifications/persistence/3.2/apidocs/jakarta.persistence/jakarta/persistence/column) * to add new fields * to change a field’s [attribute converter](https://jakarta.ee/specifications/persistence/2.2/apidocs/javax/persistence/attributeconverter) * to mark a field as nullable/not nullable * to add an [attribute override](https://jakarta.ee/specifications/persistence/3.2/apidocs/jakarta.persistence/jakarta/persistence/attributeoverride) * to add dynamic [filters](https://thorben-janssen.com/hibernate-filter/) to entities at runtime To customize these entities, you’ll need to override the default entity class that contains the fields affected. The following steps outline how to correctly configure your custom entity classes: ## 1. Copy the existing entity class to your project with the same class and package names It is critical that the class and package names remain the same so that the `EntityManager` recognizes your custom entity class as an override of the default entity class and doesn’t treat it as a new entity. For example, to customize the `description` field of `SignOffProcessDefinitionEntity` class, you need to create a `AWorkflowProcessDefinitionEntity.java` file at the following path in your project: ``` .//com/activeviam/workflow/core/model/definition/jpa/AWorkflowProcessDefinitionEntity.java ``` Where `` is the path from the root of your project to the directory containing your `.java` files, typically `src/main/java`. ## 2. Modify the entity class as needed Removing or renaming existing fields may break Atoti Sign-Off. You can now modify the entity class as needed. The following example doubles the length of the `description` field from the default of 4000 characters to 8000 and adds a new `comment` field with a length of 1000 characters, all other fields and methods remain unchanged: ```java theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}} @MappedSuperclass @Getter @Setter public abstract class AWorkflowProcessDefinitionEntity> extends ABitemporalObjectEntity implements IProcessDefinition { private static final long serialVersionUID = -4062921677920109539L; @Column(name="name", nullable=false) private String name; @Column(name="description", length = 8000) @Size(max=8000) private String description; @Column(name="comment", length = 1000) @Size(max=1000) private String comment; @Column(name="category") private String category; @Column(name="workflowType") private String workflowType; @Column(name="workflowProperties", length = 4000) @Convert(converter = ParametersConverter.class) @Size(max=4000) private Map workflowParameters; @Column(name="serverName", length = 4000) @Size(max=4000) private String serverName; @Column(name="domain", length = 4000) @Size(max=4000) private String domain; @Column(name="filters", length = 4000) @Convert(converter = FiltersConverter.class) @Size(max=4000) private List> filters; @Column(name="kpis", length = 4000) @Convert(converter = KpisConverter.class) @Size(max=4000) private List kpis; @Override public String getKey() { return getKey(getName()); } @Override protected void setKeys(String... keys) { name = keys[0]; } @Override public int hashCode() { return Objects.hash(super.hashCode(), name, category, description, workflowType, workflowParameters, domain, filters, kpis); } @Override public boolean equals(Object obj) { return super.equals(obj) && Objects.equals(name, ((AWorkflowProcessDefinitionEntity)obj).name) && Objects.equals(category, ((AWorkflowProcessDefinitionEntity)obj).category) && Objects.equals(description, ((AWorkflowProcessDefinitionEntity)obj).description) && Objects.equals(workflowType, ((AWorkflowProcessDefinitionEntity)obj).workflowType) && Objects.equals(workflowParameters, ((AWorkflowProcessDefinitionEntity)obj).workflowParameters) && Objects.equals(domain, ((AWorkflowProcessDefinitionEntity)obj).domain) && Objects.equals(filters, ((AWorkflowProcessDefinitionEntity)obj).filters) && Objects.equals(kpis, ((AWorkflowProcessDefinitionEntity)obj).kpis); } } ``` If you have an existing database, and you modify the physical structure of the data in your schema, you may need to migrate the schema in order for your changes to take effect. The next time you start Atoti Sign-Off, it will use your custom entity class for the `SignOff Process Definition` managed object. You can verify the change is applied by checking the schema for the `processDefinition` table in your database to verify that the `description` column has a length of 8000 and that the new `comment` column exists: Custom SignOff Table Schema