Mongodb Collection Not Complete

[Nigel David]

I just set up SlamData hoping to use it to create dashboards for time series data in a mongodb.

One of my collections is missing a key piece of information.

[Damon LaCaille]

Nigel - can you provide more details? There isn't much context here to go on.

[Nigel David]

Sure. The above screenshots show the difference between my "Topics" collection as shown in SlamData (top) and in the mongo shell (bottom).

When I open the "topics" collection in Slamdata the preview does not show the id corresponding to each topic name.  

This collection is meant to provide the key mapping between the sensor and the id. Only the id is recorded subsequently with the time series collection.

Any idea why this might be?

THanks

[do...@slamdata.com]

Hi Nigel, unless you specifically select out the _id value when writing your query, you won't see it. This means going through an Open card you will not see the _id field in a Preview Table. If you want to see the _id value, you have to use a Query card with code similar to the following:

select

        `_id`

    ,   topic_name

from

        `/mount/db/topics`

That being said, the value is accessible to you in queries, even though we don't show it by default when running queries.

Hopefully this helps.

[Nigel David]

Hi,

I ran the above query successfully using a query card, but when I follow that with a preview table card I still don't see the _id data.

[do...@slamdata.com]

Sorry about that Nigel. I forgot we to alias the `_id` field to get it to show.

Change the query I provided as follows:

select

        `_id` as ID

    ,   topic_name

from

        `/mount/db/topics`

[Nigel David]

Great. Thanks!