HarmonyOS NEXT 中级开发笔记：出行地图应用中的数据库设计与实践

import relationalStore from '@ohos.data.relationalStore';
const STORE_CONFIG = {  name: 'TravelMap.db',  securityLevel: relationalStore.SecurityLevel.S1};
let rdbStore;relationalStore.getRdbStore(this.context, STORE_CONFIG, (err, store) => {  if (err) {    console.error(`Failed to get RdbStore. Code:${err.code},message:${err.message}`);    return;  }  rdbStore = store;  // 创建地点收藏表  const sql = `CREATE TABLE IF NOT EXISTS favorite_places (    id INTEGER PRIMARY KEY AUTOINCREMENT,    name TEXT NOT NULL,    latitude REAL,    longitude REAL,    timestamp INTEGER  )`;  rdbStore.executeSql(sql);});

// 添加收藏地点async function addFavoritePlace(name: string, lat: number, lng: number) {  const valueBucket = {    'name': name,    'latitude': lat,    'longitude': lng,    'timestamp': new Date().getTime()  };  try {    await rdbStore.insert('favorite_places', valueBucket);    console.info('Add favorite place successfully.');  } catch (err) {    console.error(`Failed to add place. Code:${err.code},message:${err.message}`);  }}
// 查询收藏列表async function queryFavorites() {  const predicates = new relationalStore.RdbPredicates('favorite_places');  predicates.orderByDesc('timestamp');  try {    const result = await rdbStore.query(predicates, ['id', 'name', 'latitude', 'longitude']);    return result.allObjects(); // 返回对象数组  } catch (err) {    console.error(`Failed to query places. Code:${err.code},message:${err.message}`);    return [];  }}