(`Select` Feature)Is there a way to only return all records of only 1 column

[c-emin]

Using your Person Data Collection from the example...

I would like to query the Table and only return the Data for column _Age.

I know I can do a GetAll, and then get the single column from that...
I'm just trying to keep things fast and only querying data that is needed.

Something like this would be nice:

var AllThePeeps = await manager.GetAll();

var AllTheAges = await manager.GetAll<Person,_Age>();

[yueyinqiu]

Hmm... I don't think this can be done simply.

First manager.GetAll<Person,_Age>() is not a valid expression in C#. A possible substitute might be manager.GetAll<Person>(x => x._Age). And that requires us to resolve the expression tree x => x._Age and properly pass it to JavaScript layer.

And at the meantime, others may also like x => (x._Age, x._Name), so finally it should become something like IQueryable, which allows you to use Where, Select and some more LINQ methods.

So maybe a deeper consideration is required about this issue.

[magiccodingman]

@yueyinqiu @c-emin Actually I think I can do this. It's simply a deferred execution of "Select(x => x._Name)". I've sadly clocked too much time on my most recent PR for this project and need to focus on other things for a bit. But I do not think this is that crazy of an additional feature. Actually a really good feature. But I brought up a pretty major concern and scalability feature here:
#37

And I'd like to resolve that first prior to coming back to this, but I will note this as a feature request. Because I have some good ideas to pull it off and there's tons of use cases for this.

[c-emin]

I know you have been working on a lot of other features/issues.
Just curious, if this Feature Request will be completed in the next week or so?

I did like your suggestion on allowing multiple field names! x => (x._Age, x._Name)

[magiccodingman]

I'd love to promise a week or so, but I really can't sadly. I work 12-16 hour days for my company. Do I think I'll get it done in 30 days? I think so. But just don't want to make promises I can't keep.

But I do agree about multiple from the select. I was thinking of making it work nearly identical to the current Select. So you can choose to have it go to one thing or to an object

[magiccodingman]

@c-emin I made this new feature request where this would be tied into it:
#47

I won't be able to promise the month timeline though. I've got some code base crisis issues that has eaten up my time significantly. I dumped already more time into this project for fun than I should of and after this update #43 which is a monster of an update, which was somehow larger than #38

These updates have opened up a world of possibilities. And with the newly created Issue 47 this will become a likely reality!

But I have to drop off and put out fires 🔥so hopefully next month I can spend time refactoring the expression builder and bringing to life more LINQ like capabilities.

I'm going to close this ticket since I've already documented this as a necessity for another feature. Have a good one.

[magiccodingman]

Re-opening ticket because I decided to separate it from #47
As I brought up before, I did see this as possible. The new update #26 brings this into reality.

With the new Cursor querying logic implemented. Though the Select isn't available yet. We can implement new logic and utilize a cursor to grab efficiently only what we want. Thus very similarly emulating a "Select" statement in LINQ.

[c-emin]

@magiccodingman

Does the new version of Magic IndexedDB v2.0.0-alpha1, solve this issue?

[magiccodingman]

@c-emin Not the alpha1 release no, but I did build the foundation to allow this capability moving forward. It's actually on my to do list. I'll be adding Min, Max, and Select in upcoming updates. It'll be a true Select as well! Which is very exciting!

Basically with the new cursor engine, I can grab only specific parts of the data. Like genuinely, no illusion. So no loading the full item into memory then passing only 1 piece back. But just grabbing only what you requested. Very exciting! Sadly not on the first alpha1 drop, but I have built the groundwork to see this feature come to life as I want it too!