---
description: >-
  Takes as parameter a stringified object and another object, converts, maps,
  and returns the stringified object with the updated properties.
  Non-entity-type properties are discarded.
---

# UpdateString

No mapper:

```typescript
const example: Example = {
  data: "{\"name\": \"example\",\"description\": \"this is an example\",\"extra\": \"\",\"size\": \"123\", \"price\": 100}",
}

const inputData: IExampleDTO = {
  name: undefined,
  description: "this is a new description",
  extra: "this is an extra",
  size: undefined,
  price: 20,
};

const updatedData = JSON.parse(example.data)

updatedData.name = inputData.name,
updatedData.description = inputData.description,
updatedData.extra = inputData.extra,
updatedData.size = inputData.size,
updatedData.price = inputData.price,

await this.examplesRepository.update(
  {
    ...example,
    data: JSON.stringify(updatedData),
  },
  trx,
);

output => example.data = "{\"name\": \"\",\"description\": \"this is a new description\",\"extra\": \"this is an extra\",\"size\": \"\", \"price\": 20}";
```

Using mapper:

```typescript
import { updateString } from "@utils/mappers";

const example: Example = {
  data: "{\"name\": \"example\",\"description\": \"this is an example\",\"extra\": \"\",\"size\": \"123\", \"price\": 100}",
}

const inputData: IExampleDTO = {
  name: undefined,
  description: "this is a new description",
  extra: "this is an extra",
  size: undefined,
  price: 20,
};

await this.examplesRepository.update(
  {
    ...example,
    data: updateString(example.data, inputData),
  },
  trx,
);

output => example.data = "{\"name\": \"\",\"description\": \"this is a new description\",\"extra\": \"this is an extra\",\"size\": \"\", \"price\": 20}"
```

***
