Sort not working

[arthurquerou]

It seems that sort conditions are not taken into account.

In index.js in the Sort section you have this code:

var sort = _.keys(options.sort)[0];
      if (sort) {
          query.ascending();
        }
        else if (sort == -1) {
          query.descending();
        }

It can't even work as sort equals the key and not the value.

Are there any plan to update this behaviour ?

[ferrants]

Trying to work this out myself as well. According this library: https://github.com/ryanfitz/vogels, For non-scanning queries, sort requires indicating an Index to use if you're not using the primary index of the table. You can't or shouldn't be able to sort on an arbitrary field using dynamo unless you're using scan. The ascending/descending should respect the range field of the index you're using.

Looks like the index is set around line 546: https://github.com/gadelkareem/sails-dynamodb/blob/master/index.js#L546

          if (indexName && indexName != 'primary') {
            query.usingIndex(indexName);
          }

Regardless of this, the lines you posted don't make sense for the handling of the sort. It gets the first key in the sort dictionary and expects that to be -1 for descending or 1 for ascending. The number -1 can not be the key of a dictionary, so you can never have descending. sort: {-1: something} doesn't make sense. I think it should be:

sort: {indexName: -1}

to sort that index in a descending way.

I made https://github.com/gadelkareem/sails-dynamodb/pull/35 to see if that works

[ferrants]

You can use sort: "-1" to descendingly sort based on whatever index it picks up. The sort variable ends up being { '-1': 1 }, which seems to work. My Pr didn't work.

[ferrants]

I made https://github.com/gadelkareem/sails-dynamodb/pull/36 for a documentation update to show how this feature works for this adapter

[jkeczan]

When I sort by a -1, I am getting query.descending not a function defined on line 897.

Any thoughts?

TypeError: query.descending is not a function
    at Object._searchCondition (/Users/jkeczan/Projects/web/external/straingauge-web/node_modules/sails-dynamodb/index.js:897:17)
   

[ferrants]

My thoughts are that you may not have an index on what you are searching by or ordering by so it's trying to do it in scan mode instead of query mode.

[ggarcia92]

Hi, I'm trying to sort by updatedAt but when I define an index to that attribute on model and lunch local dynamodb throws this error "Cannot read property 'dynamoType' of undefined". Is this a bug?

[ferrants]

Doesn't sound like a bug or this open issue. Sounds like a configuration issue.