[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Schema](https://evolu.dev/docs/api-reference/common/local-first/Schema) › NullableColumnsToOptional

```ts
type NullableColumnsToOptional<T> = {
  readonly [K in RequiredColumnKeys<T>]: InferOutput<T[K]>;
} & { readonly [K in OptionalColumnKeys<T>]?: InferOutput<T[K]> };
```

Defined in: [packages/common/src/local-first/Schema.ts:350](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Schema.ts#L350)

Makes columns whose output type includes `null` optional.