# W3 Data Handling

## Promise

## Fetch
https://reactnative.dev/docs/network
fetch are able to perform HTTP request, it will return a `Promise`.

## Mobile Storage

### AsyncStorage (KeyStore)
AsyncStorage is a key-value type storage, usually used for simple data.
https://docs.expo.io/versions/latest/sdk/async-storage/
https://react-native-async-storage.github.io/async-storage/docs/usage/

### SQLite (Database)
SQL is a programming language to communicate with database.
SQLite is a lightweight single file-based database which are unable to handle concurrence well.

Learn and practice SQL: https://www.w3schools.com/sql/
Expo SQLite: https://docs.expo.io/versions/latest/sdk/sqlite/