Same query producing a different result?

[devfelipereis]

Case

BUG

Issue

Same query producing a different result.

Info

• Environment: Ionic 3
• Adapter: IndexedDB
• Stack: Typescript, Angular, Ionic

@ionic/app-scripts : 3.1.8
Cordova Platforms : android 7.0.0
Ionic Framework : ionic-angular 3.9.2

"pouchdb-adapter-http": "^6.4.3"
"pouchdb-adapter-idb": "^6.4.3"
"rxdb": "^7.4.4"
"rxjs": "5.5.8"

Code

  db.collections['post']
      .find({
        $and: [
          { event_id: { $eq: 2 } },
          { user_id: { $eq: '6' } },
          { created_at: { $gt: null } },
        ],
      })
      .sort({ created_at: 'desc' })
      .exec().then(data => console.log(data));

 db.collections['post']
      .find().where('event_id').eq(2).where('user_id').eq('6').where('created_at').gt(null)
      .sort({ created_at: 'desc' })
      .exec().then(data => console.log(data));

I'm new with rxdb but I think that this queries do the same thing, right?

In the first query I also get results that "event_id" is equals 1. In the second query this does't happen.
Any ideia?

[pubkey]

Your queries are correct. This looks like a bug. Can you submit a failing PR to reproduce this? You can start by editing this file: https://github.com/pubkey/rxdb/blob/master/test/unit/bug-report.test.js

[pubkey]

I could not reproduce this with the attached test. Please reopen this with a reproducing test-case

[gvuyk]

I've been tracking this bug/feature? for a little while now and I think I found it.
When you make 2 equal queries, the second just returns the cached results from the first (that is, if the cache wasn't invalidated by an insert or something else), now, if you alter the results array from the first query, the second returns the same altered results

How to reproduce

docs = await collection.find({}).exec()    // docs.length == x
docs.splice(0, 1);                         // docs.length == x-1
docs = await collection.find({}).exec()    // docs.length == x-1

Is this your case @devfelipereis?

[pubkey]

@gvuyk that might be the case. I think exec() then should always return a new array to prevent this.

[devfelipereis]

Hello. Sorry for being late...
@gvuyk @pubkey Look at this:

Results

Look that in _data object, event_id is 1. In my query I'm looking for 2.

Post schema

{
  "title": "post schema",
  "description": "describes a post",
  "version": 0,
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "primary": true
    },
    "event_id": {
      "type": "number"
    },
    "user_id": {
      "type": "string",
      "ref": "user"
    },
    "text": {
      "type": "string"
    },
    "photo": {
      "type": ["string", "null"]
    },
    "created_at": {
      "type": "string",
      "index": true
    },
    "likes_count": {
      "type": "number"
    },
    "comments_count": {
      "type": "integer"
    },
    "user": {
      "type": "object",
      "properties": {
        "data": {
          "type": "object",
          "properties": {
            "name": {
              "type": "string"
            },
            "photo": {
              "type": "string"
            }
          }
        }
      }
    }
  }
}

EDIT

I close the app after posting this. Then I open again to do another test. Now I'm not getting that results.

[pubkey]

@devfelipereis have you enabled the query-change-detection?

[pubkey]

@gvuyk I fixed the problem with mutating result-arrays.
@devfelipereis Please create a test, screenshots do not really help. I believe you that there is a problem, you do not have to create further evidence. We need something that I can use to reproduce and fix this.