Manually update Apollo Graphql Cache

Usually you structure your graphql queries and mutations in a way that the cache just works out of the box. But there are times that you need to manually update the graphql cache then you can call `updateQuery`:

```js
const client = useApolloClient();
const preferences = {abc: "xyz"};

function updateCache() {
  client.cache.updateQuery({ query: MY_QUERY }, (data) => {
    if (!data.preferences) {
      return { ...data, preferences };
    }
  });
}
```

Note that the `return` is optional, so if your update function returns `undefined` then it will keep the cache intact, without updating anything.

gabrielreis

September 26, 2023