Collection.count / Query.count

# Collection.count / Query.count

Calculates the number of records in the collection or number of result records corresponding to the query statement. Note that it is related to the setting of collection permission, and a user can only calculate the number of records that he/she has permission to read.

Function signature is shown as below:

function count(options?: object): Promise<Result>

Parameter description

options is an optional parameter, an object with the following format. For example: if one of success, fail and complete is passed in, it means the callback style is used, and Promise is not returned.

Field	Type	Required	Description
success	Function	No	Callback succeeds. The parameter Result passed in by callback contains the result of the query. The Result is defined as below.
fail	Function	No	Callback fails
complete	Function	No	Callback function when call completes (always executed whether call succeeds or fails)

Description of return value

If the options parameter is not passed, or the incoming options parameter does not have a success, fail or complete field, a Promise will be returned or otherwise no value is returned. The results of resolve and reject for Promise are defined as below:

	Result Description
resolve	The result of query. The Result is defined as below.
reject	Reason for failure

Result description

The result of success callback and Result of resolve for Promise are objects with the following structure:

Field	Type	Description
total	number	Number of results

Sample code

Get total number of my to-dos

Callback style

const db = wx.cloud.database()
db.collection('todos').where({
  _openid: 'xxx' // Enter the current user openid
}).count({
  success: function(res) {
    console.log(res.total)
  }
})

Promise style

const db = wx.cloud.database()
db.collection('todos').where({
  _openid: 'xxx' // Enter the current user openid
}).count().then(res => {
  console.log(res.total)
})