# Entity Inheritance Hierarchy {#entity-inheritance-hierarchy}


Understanding the base class hierarchy for all database entities.


## Inheritance Tree {#inheritance-tree}






```mermaid
classDiagram
    class BaseEntity {
        +id: UUID
        +createdAt: Date
        +updatedAt: Date
    }

    class TenantBaseEntity {
        +tenantId: UUID
        +tenant: Tenant
    }

    class TenantOrganizationBaseEntity {
        +organizationId: UUID
        +organization: Organization
    }

    class TranslationBase {
        +languageCode: string
    }

    BaseEntity <|-- TenantBaseEntity
    TenantBaseEntity <|-- TenantOrganizationBaseEntity
    BaseEntity <|-- TranslationBase
```






## BaseEntity {#baseentity}


The root class for all entities:

```typescript
export abstract class BaseEntity {
  @PrimaryGeneratedColumn("uuid")
  id: string;

  @CreateDateColumn()
  createdAt: Date;

  @UpdateDateColumn()
  updatedAt: Date;

  @Column({ nullable: true })
  isActive?: boolean;

  @Column({ nullable: true })
  isArchived?: boolean;

  @DeleteDateColumn()
  deletedAt?: Date;

  @Column({ nullable: true })
  archivedAt?: Date;
}
```


## TenantBaseEntity {#tenantbaseentity}


Adds tenant scoping:

```typescript
export abstract class TenantBaseEntity extends BaseEntity {
  @Column({ nullable: true })
  tenantId: string;

  @ManyToOne(() => Tenant)
  tenant?: Tenant;
}
```

**Usage:** Entities scoped to a tenant but not organization-specific (e.g., Role, User settings).


## TenantOrganizationBaseEntity {#tenantorganizationbaseentity}


Adds organization scoping:

```typescript
export abstract class TenantOrganizationBaseEntity extends TenantBaseEntity {
  @Column({ nullable: true })
  organizationId: string;

  @ManyToOne(() => Organization)
  organization?: Organization;
}
```

**Usage:** Most business entities (Task, Employee, Invoice, etc.).


## TranslationBase {#translationbase}


For multi-language content:

```typescript
export abstract class TranslationBase extends BaseEntity {
  @Column()
  languageCode: string;
}
```

**Usage:** ProductTranslation, ProductCategoryTranslation, etc.


## Which Base Class to Use {#which-base-class-to-use}


| Scenario                   | Base Class                     |
| -------------------------- | ------------------------------ |
| System-level entity        | `BaseEntity`                   |
| Tenant-scoped              | `TenantBaseEntity`             |
| Organization-scoped (most) | `TenantOrganizationBaseEntity` |
| Translatable content       | `TranslationBase`              |


## Related Pages {#related-pages}


- [Core Entities](https://sourcey-gauzy.pages.dev/database/entity-reference/core-entities/index.md) — User, Tenant, Org
- [Multi-ORM Deep Dive](https://sourcey-gauzy.pages.dev/advanced/multi-orm-deep-dive/index.md) — ORM decorators
- [Plugin Development Guide](https://sourcey-gauzy.pages.dev/plugins-built-in/plugin-development-guide/index.md) — using base classes