要实现“本地数据库 + 服务器数据库 - React Native”的解决方法,可以按照以下步骤进行:
npm install react-native-sqlite-storage axios
import SQLite from 'react-native-sqlite-storage';
SQLite.DEBUG(true);
SQLite.enablePromise(true);
const databaseName = 'mydb.db';
const databaseVersion = '1.0';
const databaseDisplayName = 'My Database';
const databaseSize = 200000;
const db = SQLite.openDatabase({
name: databaseName,
version: databaseVersion,
displayName: databaseDisplayName,
size: databaseSize,
});
db.transaction((tx) => {
tx.executeSql(
'CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, email TEXT)'
);
});
import axios from 'axios';
const getUsersFromServer = async () => {
try {
const response = await axios.get('https://example.com/users');
const users = response.data;
// 处理获取到的用户数据
} catch (error) {
console.error(error);
}
};
const syncData = async () => {
try {
const response = await axios.get('https://example.com/users');
const users = response.data;
db.transaction((tx) => {
tx.executeSql('DELETE FROM users');
users.forEach((user) => {
tx.executeSql('INSERT INTO users (name, email) VALUES (?, ?)', [
user.name,
user.email,
]);
});
});
} catch (error) {
console.error(error);
}
};
const getUsersFromLocalDB = async () => {
try {
const users = await new Promise((resolve, reject) => {
db.transaction((tx) => {
tx.executeSql('SELECT * FROM users', [], (_, { rows }) => {
resolve(rows.raw());
}, reject);
});
});
// 处理本地数据库中的用户数据
} catch (error) {
console.error(error);
}
};
通过以上步骤,你可以实现“本地数据库 + 服务器数据库 - React Native”解决方案,即通过React Native SQLite创建和操作本地数据库,通过Axios库连接服务器数据库并获取数据,并将服务器数据同步到本地数据库中。