How to Angularfire2 remove() by some key value

问题

I am trying to delete comments of a particular thread orderby some key(sid) value.

eComments
 0b4080bb4e686f003aaa340f8ed2e2a6
   cid: "0b4080bb4e686f003aaa340f8ed2e2a6"
   comment: "Prison Break revolves around two brothers: one ..."
   createdAt: 1487250871623
   rating: 0
   sid: "c088239a29827946f932f73c9a1d495a"
   uid: "SFmtrI0ta5PsqYkgqZuJo2"
   updatedAt: 1487250871623

4bde9de83ac2bb6d06df9876c2294483addclose
   cid: "4bde9de83ac2bb6d06df9876c2294483"
   comment: "arrives at the jail, he meets the prison denize..."
   createdAt: 1487251466761
   rating: 0
   sid: "e8c2d3c2aaf877fcdf0c103229645981"
   uid: "SFmtrI0ta5PsqYkgqZuJo2E"
   updatedAt: 1487251466761

Let say I wanted to delete sid: "c088239a29827946f932f73c9a1d495a" I tried this, but unfortunately it deletes all the eComments database

const commentList = this.af.database.list('/eComments', {
      query: {
        orderByChild: 'sid',
        equalTo: sid
      }
    });
commentList.remove();

Anyway I can delete by key value?

回答1:

This is one way:

const commentList = this.af.database.list('/eComments', {
      preserveSnapshot: true,
      query: {
        orderByChild: 'sid',
        equalTo: sid
      }
    });
commentList.subscribe(snapshots=>{
    snapshots.forEach(snapshot => {
      snapshot.ref.remove();
    });
})

I am not an AngularFire2 expert, so there might be easier/more idiomatic ways.

来源：https://stackoverflow.com/questions/42275384/how-to-angularfire2-remove-by-some-key-value