【HarmonyOS】云开发-云数据库（二）

背景

书接上回，实现了云侧和端侧的云数据库创建、更新、修改等操作。这篇文章实现调用云函数对云数据库进行增删改查。

CloudProgram 项目配置

新建函数

在cloudfunctions目录下点击右键，选择新建Cloud Function，输入query-student-function

导入SDK

在终端中切换到当前云函数的目录下

安装SDK

npm install --save @hw-agconnect/cloud-server

导入云数据库类型

选择云数据库需要导出的json文件，右键选择Generate Server Model

选择存放的目录，例子直接放在云函数下，方便调用

可以看到云函数目录下多出一个ts文件

使用云函数调用云数据库

引入 @hw-agconnect/cloud-server 和云数据库对象类。
这个云函数实现的功能是，查询test存储区下，所有的t_Student的数据，并返回查询内容。

import { cloud, CloudDBCollection } from '@hw-agconnect/cloud-server';
import { t_Student } from './t_Student';let myHandler = async function (event, context, callback, logger) {logger.info(event);let collection: CloudDBCollection<t_Student> =cloud.database({ zoneName: "test" }).collection(t_Student)let result = await collection.query().get();return callback({code: 0,desc: "SUCCESS" ,result});
};export { myHandler };

上传云函数

在云函数上右键，选择上传到云端。

在AGC上查看是否上传成功

在云端测试云数据库的获取，确定云数据库访问没有问题

Application端配置

1.项目配置

在AGC中的项目项目设置中导出agconnect-services.json文件，并放到项目的src/main/resources/rawfile目录下。

2.安装SDK

在终端中切换到entry目录

在entry的目录下，安装SDK

ohpm install @hw-agconnect/hmcore
ohpm install @hw-agconnect/cloud

这样子显示安装进度，就是安装成功了

然后去oh-package.json5文件中去查看是否安装成功

3.初始化云模块

在EntryAbility.ets项目的onCreate方法下，调用数据库初始化

import { abilityAccessCtrl, AbilityConstant, PermissionRequestResult, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';
import { initialize } from '@hw-agconnect/hmcore';
import servicesJson from '../../resources/rawfile/agconnect-services.json';export default class EntryAbility extends UIAbility {onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {try {initialize(this.context, servicesJson);} catch (e) {hilog.error(0x0000, 'AGConnectError', JSON.stringify(e));}let AtManager = abilityAccessCtrl.createAtManager();AtManager.requestPermissionsFromUser(this.context, ['ohos.permission.READ_MEDIA', 'ohos.permission.MEDIA_LOCATION']).then((data: PermissionRequestResult) => {hilog.info(0x0000, 'testTag', '%{public}s', 'request permissions from user success' + data);}).catch((err: Object) => {hilog.error(0x0000, 'testTag', 'Failed to request permissions from user. Cause: %{public}s',JSON.stringify(err) ?? '');});hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');}onDestroy(): void {hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy');}onWindowStageCreate(windowStage: window.WindowStage): void {// Main window is created, set main page for this abilityhilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');windowStage.loadContent('pages/Student_Page', (err, data) => {if (err.code) {hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');return;}hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');});}onWindowStageDestroy(): void {// Main window is destroyed, release UI related resourceshilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageDestroy');}onForeground(): void {// Ability has brought to foregroundhilog.info(0x0000, 'testTag', '%{public}s', 'Ability onForeground');}onBackground(): void {// Ability has back to backgroundhilog.info(0x0000, 'testTag', '%{public}s', 'Ability onBackground');}
}

4.项目中调用云函数

新建接受返回结果类Student

export class Student {public id: number | undefined;public name: string | undefined;public age: string | undefined;
}

添加引用

import cloud, { FunctionResult } from '@hw-agconnect/cloud';
import { JSON } from '@kit.ArkTS';
import { Student } from '../Model/Student';

UI调用

import cloud, { FunctionResult } from '@hw-agconnect/cloud';
import { JSON } from '@kit.ArkTS';
import { Student } from '../Model/Student';@Entry
@Component
struct Student_Page {@State message: string = 'Hello World';build() {Column() {Text(this.message).fontSize(20)Button("查询数据").width("80%").margin({ top: 20 }).onClick(async () => {let funResult: FunctionResult = await cloud.callFunction({name: "query-student-function",})let student: Student[] = funResult.getValue().result;this.message = JSON.stringify(student);})}.height('100%').width('100%')}
}