Cascade & Unique Constraints

Cascade Configuration

Define parent-to-children relationships to automatically cascade soft-delete and restore operations.

SoftDeleteModule.forRoot({
  softDeleteModels: ['User', 'Post', 'Comment'],
  cascade: {
    User: ['Post'],
    Post: ['Comment'],
  },
  maxCascadeDepth: 3,
  prismaServiceToken: PrismaService,
});

When a User is soft-deleted, all their Post records are soft-deleted automatically, and each post's Comment records are soft-deleted as well. Restoring the User reverses the entire tree up to maxCascadeDepth levels deep.

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Unique Constraint Strategy

Standard @unique constraints break when multiple soft-deleted rows share the same value (e.g. two deleted users with the same email). Use a composite unique constraint that includes deletedAt:

model User {
  id        Int       @id @default(autoincrement())
  email     String
  deletedAt DateTime?

  @@unique([email, deletedAt])
}

This allows multiple soft-deleted rows with the same email while still enforcing uniqueness among active records (where deletedAt IS NULL). Note that this works in most databases because NULL values are treated as distinct in unique indexes. Verify this behaviour for your specific database engine.