Order by results in "is not a function"

[endor...@gmail.com]

Hi everyone,
i am new to DEXIE and everything works perfect until i want to
order my result.

This is my code:

db.playlists
.orderBy('widPosition')
.where('widStatus')
.equals('true').

the widStatus is saved as string. I if remove the "orderBy" line
from the code, it works. I can make DEXIE show me those entries where
the widStatus either is true or false.

But as soon as i activate the orderBy, it does not work anymore.
Can anyone point me to what i am missing? Where is the error?

Thanks in advance and greetings!
Carlos

[David Fahlander]

orderBy() returns a Collection and the Collection doesn't have where()

You could do filter() instead of where() if you want the db to sort the results. See API reference and specifically Collection.filter().

[David Fahlander]

Another option is to do Table.where() and use sortBy() instead of orderBy() at the end.

[endor...@gmail.com]

Thanks. I will try that. Let me take the opportunity to thank you for Dexie.
I still need to learn about the differences between collections and tables.
To learn it i will try both of your solutions. Thanks again!

BTW: i am doing a Chrome app with the framework7 framework and the content is based on Dexie. Can i put your logo inside it together with "Database by Dexie"

Thanks and greeting!

[endor...@gmail.com]

On Friday, June 10, 2016 at 4:13:01 PM UTC+1, David Fahlander wrote:
> Another option is to do Table.where() and use sortBy() instead of orderBy() at the end.

Can you direct me where i am going wrong with my code?

db.playlists

.where('widStatus')
.equals('true')

.sortBy('widPosition')
.each(function(oneItem){.....

[endor...@gmail.com]

[SOLVED]
After the each i had a "finally()".
I found out that i have to put the sortBy at the very end after the finally.
Just like David said.
Thanks so much!

[David Fahlander]

sortBy() returns a Promise of an array. You can't use each() on a promise but you can do forEach on the resulting array.

[David Fahlander]

Yes you may endorse Dexie in your app. That's always nice.

I'm glad you like Dexie and I wish you good luck with your app! I would advice you to read the api reference for every method you are using because it's hard to guess what class is returned without reading it. I would also advice you to read about Promises to understand how to use them properly. There's a good blog post by Nolan Lawson that I can recommend, https://pouchdb.com/2015/05/18/we-have-a-problem-with-promises.html.

Finally, if you're making a chrome app, you will be safe to use the yield keyword to consume promises. Read https://github.com/dfahlander/Dexie.js/wiki/Simplify-with-yield to learn more about that. It will simplify your code a lot.

Cheers, /D

[Carlos Pinto]

sorry for disturbing with this subject again. I searched for any "foreeach" example on the net but could not find it. And within the Dexie samples i could not

find an example showing the correct usage. In theory i understand what you explained to me and i do love the promise solution that Dexie uses.

But i can not find out where to use the foreach instead of the Dexie each() solution.

This is my code a bit shortend:

var dataPlaylist= new Array();

db.playlists

.where('widStatus')

.equals('true')

.each(function(oneItem){

            var itemTemp = {

                "dataplID" : oneItem.plID,

                "dataWidID" : oneItem.widID,

                "dataDuration" : oneItem.widDuration,

                "dataPos" : oneItem.widPosition,

            };  

            dataPlaylist.push(itemTemp); 

            slideNum++;

        })

        .finally(function() {

            data = dataPlaylist;

            for(var i in data){

                var idd = data[i].dataDuration;

                //console.log('time is:'+idd);

            }

        })

        .sortBy('widPosition');

What i am trying to is to use the widPosition to sort.

I can not use the index because that is used as reference to be deleted.

The widPosition is saved as integer.

Thanks in advance for your time and support!