在 angularfire 7 中使用带有查询参数的 listVal 和 angular 13

Question

I have started using latest angular 13 with angularfire 7 and firebase 9 and my code to query data is like below:

import { Database, objectVal, ref, listVal, update } from '@angular/fire/database';

  constructor(public db: Database) { }

return new Promise((resolve, reject) => {
      const doc = ref(this.db, "/users/" + userKey + "/cards");
      listVal(doc).subscribe(
        (res:any) => {
            resolve(res)
        },
        err => {
            console.log(err)
            reject(err)
        }
      )}
    )

I want to pass a orderBy query to it like orderByChild('_date') and could not find in the docs. The docs referred is https://github.com/angular/angularfire/blob/master/samples/modular/src/app/database/database.component.ts

I see listVal accepting the Query param but don't see how to do it.

Answer 1

here is how to do it

import { Database, objectVal, ref, listVal, update, query, orderByChild } from '@angular/fire/database';

  constructor(public db: Database) { }

return new Promise((resolve, reject) => {
      const doc = ref(this.db, "/users/" + userKey + "/cards");
      const qry = query(doc, orderByChild('_date'))
      listVal(qry).subscribe(
        (res:any) => {
            resolve(res)
        },
        err => {
            console.log(err)
            reject(err)
        }
      )}
    )