//调用云函数课程数量减1
wx.cloud.callFunction({
                name:"minusCourseNum",
                data:{
                  courseName:courseName
                }
              }).then(res=>{
                wx.showToast({
                  title: '选课成功',
                })
              })
              this.data.disable = true
//云函数
// 云函数入口文件
import { init, database } from 'wx-server-sdk'
init()
const db = database()
console.log('Database connection:',db)


const _ = db.command


// 云函数入口函数
export async function main(event,context) {
  const courseCollection = db.collection("course")
  return await courseCollection.where({
      courseName:event.courseName
  }).updata({
    data:{
      num:_.inc(-1)
    }
  })
}