May 20, 2021 WeChat Mini Program Development Document
Count the number of collection records or the number of result records corresponding to the statistical query statement, note that this is related to the collection permission setting, a user can only count the number of records whose read permissions.
The function signature is as follows:
function count(options?: object): Promise<Result>
Parameter Description
Options is an optional parameter, a object, such as one of the three Success, Fail, Complete, indicating that the callback style is used, does not return Promise.
| Field name | type | Required | Defaults | illustrate |
|---|---|---|---|---|
| success | Function | no | Successful callback, callback incoming parameter Result contains the result of the query, and the result is asked below | |
| fail | Function | no | Failed callback | |
| complete | Function | no | Call the ended callback function (successful call, failure) |
Return value description
If you don't pass the Options parameter, or the incoming Options parameter is not Success, Fail, the Complete field, returns a promise, otherwise no value is returned.The result of the promise's resolve and reject is as follows:
| Result description | |
|---|---|
| resolve | The result of the query, the result is under the definition |
| reject | Failure |
Result description
The result of the Success callback and the result of Promise Resolve Result is an object of the following structure:
| Field | type | illustrate |
|---|---|---|
| total | number | Quantity |
Sample code
Get my total number of things to do
Callback style
const db = wx.cloud.database()
db.collection('todos').where({
_openid: 'xxx' // 填入当前用户 openid
}).count({
success: function(res) {
console.log(res.total)
}
})
Promise style
const db = wx.cloud.database()
db.collection('todos').where({
_openid: 'xxx' // 填入当前用户 openid
}).count().then(res => {
console.log(res.total)
})