HarmonyOS NEXT 中级开发笔记：电器管家应用的数据库设计与操作实践

// 定义设备表结构  const DEVICE_SCHEMA: relationalStore.TableMapping = {    tableName: 'device',    columns: [      { name: 'id', type: relationalStore.FieldType.INTEGER, isPrimaryKey: true },      { name: 'name', type: relationalStore.FieldType.STRING },      { name: 'type', type: relationalStore.FieldType.STRING },      { name: 'status', type: relationalStore.FieldType.INTEGER },      { name: 'power_consumption', type: relationalStore.FieldType.FLOAT },      { name: 'last_used_time', type: relationalStore.FieldType.INTEGER }    ]  };  

// 初始化数据库  import relationalStore from '@ohos.data.relationalStore';  
let rdbStore: relationalStore.RdbStore | null = null;  
async function initDatabase() {    const config: relationalStore.StoreConfig = {      name: 'DeviceManager.db',      securityLevel: relationalStore.SecurityLevel.S1    };    rdbStore = await relationalStore.getRdbStore(this.context, config);    await rdbStore.executeSql('CREATE TABLE IF NOT EXISTS device (id INTEGER PRIMARY KEY, name TEXT, type TEXT, status INTEGER, power_consumption REAL, last_used_time INTEGER)');  }  
// 插入设备数据  async function addDevice(device: Device) {    if (!rdbStore) return;    const valueBucket: relationalStore.ValuesBucket = {      'id': device.id,      'name': device.name,      'type': device.type,      'status': device.status,      'power_consumption': device.powerConsumption,      'last_used_time': device.lastUsedTime    };    await rdbStore.insert('device', valueBucket);  }  
// 查询设备列表  async function queryDevices(): Promise<Device[]> {    if (!rdbStore) return [];    const predicates = new relationalStore.RdbPredicates('device');    const result = await rdbStore.query(predicates, ['id', 'name', 'type', 'status']);    return result.getAllObjects() as Device[];  }