index.wxml

<button class="call" bindtap="callFunction">云函数--查看</button>
<button class="call" bindtap="addFunction">云函数--添加</button>
<button class="call" bindtap="delFunction">云函数--删除</button>
<button class="call" bindtap="updateFunction">云函数--更新</button>

index.js

Page({
  //查询数据
  callFunction:function(){
    console.log("按下按钮")
    wx.cloud.callFunction({
      name:"querryData"
    }).then(console.log)
  },
  //添加数据
  addFunction:function(){
    console.log("addButton is click")
    wx.cloud.callFunction({
      name: "addData"
    }).then(console.log)
  },
  //删除数据
  delFunction: function() {
    console.log("delButton is click")
    wx.cloud.callFunction({
      name: "delData"
    }).then(console.log)
  },
  //更新数据
  updateFunction: function () {
    console.log("updateButton is click")
    wx.cloud.callFunction({
      name: "updateData"
    }).then(console.log)
  }


})

对应四个云函数
querryData

// 云函数入口文件 初始化
const cloud = require('wx-server-sdk')
cloud.init()
let db = cloud.database();
// 云函数入口函数
exports.main = async (event, context) => {
  //获取所有数据
  return await db.collection('todos').get();
 
}

addData

// 云函数入口文件
const cloud = require('wx-server-sdk')

cloud.init()
//引用database
let db = cloud.database()
// 新增数据
exports.main = async (event, context) => {
  return await db.collection("todos").add({
    data:{
      name: 'function',
      description:"this is a demo"
    }
  })
}

delData

const cloud = require('wx-server-sdk')
cloud.init()
let db = cloud.database();

exports.main = async (event, context) => {
  //doc查询id对应项 remove删除
  return await db.collection("todos").doc("1acf1de95e466bd30fa40e0b74b0f909").remove();
}

updateData

const cloud = require('wx-server-sdk')

cloud.init()
let db = cloud.database()
//更新数据
exports.main = async (event, context) => {
  return await db.collection("todos").doc('da51bd8c5e4665770fa064af1cf1ebea').update({
    data:{
      time:123,
      price:321
    }
  })
}

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