如何在Firebase数据库中执行删除操作...我只需要从Firebase数据库中删除一条记录

Question

我只想使用http方法从Firebase数据库中删除一条记录并更新一条记录。但是，有一种方法可以从数据库中删除整个记录。我不想删除整个记录。

我尝试了以下方法：

deleteJourney(journeyId : string) : Observable<void>
{
    return this.httpclient.delete<void>(`${this.baseUrl}/${journeyId}`).pipe(catchError(this.handleError));
}

---

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable, throwError } from 'rxjs';
import { HttpErrorResponse } from '@angular/common/http'; 
import { Journey } from './Model/journey.model';
import { catchError, delay } from 'rxjs/operators';

@Injectable()
export class JourneyService{


    private journeys : Journey[] = [];
    baseUrl= 'https://ticket-management12345.firebaseio.com/journey.json';

    constructor(private httpclient : HttpClient )
    {    }

    private handleError(errorResponse : HttpErrorResponse){
        if(errorResponse.error instanceof ErrorEvent){
         console.error('Client Side Error :', errorResponse.error.message)
        }
        else {
         console.error('server Side Error :', errorResponse.error)
        }
        return throwError('There is issue in service, we are working on it');
    }

    getJourney(): Observable<Journey[]>{
    return this.httpclient.get<Journey[]>(this.baseUrl).pipe(catchError(this.handleError));
    }

    addJourney(journey: Journey) : Observable<Journey>{
    return this.httpclient.post<Journey>(this.baseUrl, journey).pipe(catchError(this.handleError));
    }

    // below 3 functions are not working

    updateJourney(journey: Journey) : Observable<void>
    {
    return this.httpclient.patch<void>(`${this.baseUrl}/${journey.id}`, journey ,{
        headers: new HttpHeaders({
            'Content-Type' : 'application/json'
        })
    }).pipe(catchError(this.handleError));
    }

    getJourneyById(journeyId : number) : Observable<Journey>
    {
    return this.httpclient.get<Journey>(`${this.baseUrl}/${journeyId}`).pipe(catchError(this.handleError));
    }


    deleteJourney(journeyId : string) : Observable<void>
    {
        return this.httpclient.delete<void>(`${this.baseUrl}/${journeyId}`).pipe(catchError(this.handleError));
    }
}

我希望一条记录会被更新/删除。