Inquire about

Get a set of data

If you want to get the data of a collection , You can call... On a collection get Method to get , But usually try to avoid getting too much data at one time , Only necessary data should be obtained .
Developers can use limit Method to specify the number of records to get , But the applet side cannot exceed 20 strip , The cloud function end cannot exceed 100 strip .

db.collection('todos').get({
    
  success: function(res) {
    
    // res.data  Is a data that contains all records in the collection that have permission to access , No more than  20  strip 
    console.log(res.data)
  }
})

Get a record of data

Let's take a look at how to get a recorded data , Suppose we have a ID by todo-identifiant-aleatoire In collection todos Record on , Then we can call... Through the reference in the record get Method to get the data of the to-do ：

db.collection('todos').doc('todo-identifiant-aleatoire').get().then(res => {
    
  // res.data  Data containing the record 
  console.log(res.data)
})

Get the data of multiple records

where Method receives an object parameter , Each field in the object and its value constitute a matching condition to be met , The relationship between the fields is “ And ” The relationship between , That is, these matching conditions must be met at the same time , In this case , Is to find todos Collection _openid be equal to user-open-id And done be equal to false The record of . We can also specify the value matching a nested field in the query criteria , For example, find your yellow to-do list ：

db.collection('todos').where({
    
  _openid: 'user-open-id',
  style: {
    
    color: 'yellow'
  }
})
.get({
    
  success: function(res) {
    
    console.log(res.data)
  }
})

What if the query is greater than or less than , use db.command Of .gt function

const _=db.command
  findData(){
    
    db.collection('douban')
      .where({
    
        price: _.gt(10)  
      })
      .field({
    
        name: true,
        price: true,
      })
      .orderBy('price', 'desc') //desc Descending order 
      // .skip(1)
      // .limit(10)
      .get()
      .then(res => {
    
        console.log(res.data)
      })
      .catch(err=>{
    
        console.log(err)
      })
  },

where Only conditions can be executed “ And ” operation , If the condition is or operation ：

Single field or operation

Field value “ or ” Operation refers to specifying a field value as one of multiple values .

If the screening progress is greater than 80 Or less than 20 Of todo：

Stream writing ：

const _ = db.command
db.collection('todo').where({
    
  progress: _.gt(80).or(_.lt(20))
})

Preposition ：

const _ = db.command
db.collection('todo').where({
    
  progress: _.or(_.gt(80), _.lt(20))
})

Pre writing can also receive an array ：

const _ = db.command
db.collection('todo').where({
    
  progress: _.or([_.gt(80), _.lt(20)])
})

Cross field or operation

Cross field “ or ” Operation refers to condition “ or ”, It is equivalent to that multiple where sentence , Just meet one of them .

If the screening progress is greater than 80 Or marked as completed todo：

const _ = db.command
db.collection(‘todo’).where(_.or([
{
progress: _.gt(80)
},
{
done: true
}
]))

Other conditions

in,eq,neq,nin,exsit,mod

Get cell phone number

1. Use 2.7.0 Or above , If the app has cloud development , In the return value of the open data interface, you can use cloudID Field get （ And encryptedData At the same level ）,cloudID Valid for five minutes .
   For example button Of getphonenumber You can get the mobile phone number in the callback function of cloudID

2. When calling cloud function , The incoming data Parameters , If the value of the top-level field is through wx.cloud.CloudID Tectonic CloudID, When the cloud function is called , The values of these fields are replaced with cloudID The corresponding open data , One call can replace at most 5 individual CloudID.

//button Of getphonenumber Callback function ：
  getPhoneNumber(e) {
    
    cloudid=e.detail.cloudID
    wx.cloud.callFunction({
    
      name: 'getcontext',
      data: {
    
        phoneNumber: wx.cloud.CloudID(cloudid)
      }
    }).then(res => {
    
      console.log(res.result.event.phoneNumber.data.phoneNumber)     // cell-phone number 
    })
  }

Cloud functions ：getcontext：

// Return open data 
const cloud = require('wx-server-sdk')
cloud.init()
exports.main = async (event, context) => {
    
  const wxContext = cloud.getWXContext()
  return {
        
    event,
    openid: wxContext.OPENID,
    appid: wxContext.APPID,
    unionid: wxContext.UNIONID,
  }
}

The second way ：

<button open-type="getPhoneNumber" bindgetphonenumber="handleGetPhoneNumber"> Mobile phone number Authentication </button>

js:

 handleGetPhoneNumber(e) {
    
    let cloudID = e.detail.cloudID // Open data ID
    if (!cloudID) {
    
      app.showToast(' User not authorized ')
      return
    }
    //  Call the cloud function to get the mobile phone number 
    wx.cloud.callFunction({
    
      name: 'getphone',
      data: {
           
        weRunData: wx.cloud.CloudID(e.detail.cloudID),
      }
    })
      .then(res => {
    
        console.log(' cell-phone number ', res)
      })
      .catch(err => {
    
        console.log(' cell-phone number err', err)
      })
  }

Cloud functions getphone.js:

exports.main = async (event, context) => {
    
    //  Get basic information 
    var moblie = event.weRunData.data.phoneNumber;
    return moblie
};