Functionality of Data Question

[aharsh]

Hi All,

Before I get into it, this is a brand new project and if there's a better way to achieve results needed, please let me know.

This might not be the right forum for this content, my apologies if there's a better place for this.  I have a complex (to me) data set I need to build into an app that has a variety of search/filter options. 

I have a set of data that's tied to a person - about 20 people total. There's another set of data tied to the same people - about 260 sets of data.  I'm trying to "Join" those two lists into a gallery that I can sort/filter/search as well as a form I can submit the required fields back to the list, but I'm having a heck of a time figuring out how that works. (the reason I'm trying to build in 2 lists is so when I search by displayName, I can limit to the entries for that person by 1 - but those entries are tied to the rest of the fields in that "multiple entries" list)

I've tried figuring out how to "Patch" - which I think I can make work on the form, but not the gallery?

Please see image to help you visualize what I'm trying to do. Again, I only created the 2 lists and added a few entries.  Nothing I can't restart if there's a better way.

Thank You!

[Drrickryp]

Hi @aharsh 

I have a series on how to do this that requires that you have a basic understanding of database principles.  It starts here https://powerusers.microsoft.com/t5/News-Announcements/Database-Design-Fundamentals-and-PowerApps-An... and one of the posts has an illustrated example of how you do it. 

[aharsh]

Hi @Drrickryp 

Thank you for sharing your training posts.  They are very well written and a great primary on databases.  It's been years since I've worked on databases, so it was a good refresher.  I see I need to break up some of my lists and watch Shane's video to be more efficient and not use choice columns etc.

However, I've already done a lot of leg work for what you trained on.  I've worked to identify what is one entry to link to what are multiple entries.  My goal here is to take a very simple spreadsheet that would make your eyes bleed and turn it into an app that is easy to both navigate and update.  My agency just moved to Office from Google 2 months ago and this program combined with the rest of the office suite is so powerful, I'd like my agency to start to tap into that. (I've developed 4 apps, but they are all just fun, employee engagement apps. Nothing the executives take seriously)

You've identified how important it is to store information in more than one datasource. I get it. What I don't get is how to call multiple data sources to the SAME screen/Gallery when viewing this data.  It does me no good to have a bunch of fragmented galleries for each of my lists.

In your sample you have 2 datasets, customers and orders. You never had a screen they shared, you always interact with them on separate screens. Is this the limitation?  Or am I missing something?

Right now, SharePoint or Excel are my only options for a datasource. I prefer not to use Excel. I am building a Canvas app, I don't seem to have access to Model Driven.

I'm sharing my leg work of what I want this data to do, all it's doing is showing which organizations the 20ish HR employees service. The intent is for an employee to lookup who their HR servicing representative is for the 5 service types.   I interviewed a dozen power users to this (god awful) spreadsheet I turned into (god awful) HTML tables late last year. 

I absolutely cannot do this if I can't get the data into one gallery / display form.  Because:

Rep Name (1 entry)

Organization Supported (multiple entries)

Backup/Primay/Assistant/LM Primary Assistant (multiple, each rep has a handful of these based on which organization they are supporting,  and there's about 10 categories)

Service Offered (1 entry)

That's some of the data - and it shows it doesn't make sense to show on multiple screens like your sample app.

Sorry - too much info. I'm just not sure what other info to share to get to the information I need to learn.  Thank you for reading if you got this far 🙂

[Drrickryp · Accepted solution]

Hi @aharsh 

This is a tall order and it's getting late where I am so I won't be able to do much until after 12 pst tomorrow. However, as I said in the beginning, although it may seem insurmountable, the way to deal with a complex problem is to break it down to its components.  It sounds like you have most of the lists right.  Now you need to work on the relationships.  Each list needs a primary key.  Fortunately, SharePoint assigns an ID to every list.  So the next step is to show the relationships by putting the foreign keys in the Child lists (The many side of a one to many relationship). This is done by including a number field in the child list and name it according to the list it comes from.  So for example, Organizations and Members could be two lists providing each member could only be in one Organization.  One Organization can have many Members, so there should be OrganizationID key (foreign key)  in the Members list.   If your model requires that a Member could be in more than one organization and each organization can have many members, then this is a Many to Many relationship.  In that case, a third list will be required (Junction list).  This will be a list with at least 3 fields, its own ID, an OrganizationID and a MemberID.  Although it may seem tedious to do this analysis and create lists, please believe me that it is time well spent.  At this point, think about each list and diagram your lists according to the relationships. If you find Many to Many relationships, create another list as a junction. then  you will have two one to many relationships with the junction as the Many side of both outer lists.   
Don't worry about the gallery until you have the lists and relationships defined correctly.  As long as the lists are linked to each other with Primary keys and Foreign keys, you can always "walk" through the relationships between the lists to find the data you need.  Don't give up and remember every journey begins with a few steps. 

As an example of a complicated database, in 2000 MS Access developed a sample database for a fictional company called Northwind Traders. The tables and relationships are shown in this screenshot.  

It was extremely well designed and even now, 20 years later it still serves as a way to learn how to use common data service to design apps with PowerApps.  ref:  https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/northwind-install .  Look carefully at the tables and relationships and you will see examples of One to many and Many to many relationships. It may look complicated but essentially they are all just a foreign key inserted into the Many side of a relationship and this key is the ID field of the one side.  

Just follow me:

[aharsh]

Hi, @Drrickryp  -

Thank you for that kind explanation of the pieces I overlooked!  I took some time and built my relationships.  It's a useful exercise to see how the data all works together.  I'm very happy you're helping me with a simple data set, I can see how this would get complex quickly.  

Now....I will wait until I have a fresh day (and fresh mind) to figure out how to go from diagram to real life 🙂 I know I need to somehow have my app grab data from/write to each of these lists.   And I'm hoping the answer will be re-watching Shane Young's video.  

Thank you!

[aharsh]

Hi @Drrickryp ,

Once again, thank you for taking time to explain relational database planning to me.  I've gotten the first couple lists setup and am able to call both lists using the ID format in a form.  I'm not able to call both lists in a gallery.  I've found a handful of tutorials that explain the process, but all of them have the parent relationship in a gallery and the child in a form.  I had that working before I posted this question on another app I'm working on (parent projects, child tasks).

So, back to my original question.  Can you include both parent and child in a gallery?  And if so, can you point me to a tutorial or video because I can't find anything that says that works.

Thank you!

[Drrickryp]

Good morning @aharsh 

You simply have to use a lookup on the foreign key to show any value in the parent list.  For example, Lookup(Parent,ID=parentID, Name) or Lookup(Parent,ID=parentID, Address).  You can also create a subgallery from the child list by using the GroupBy() function.  These are called "nested galleries" and there are several videos of how to do it.  You group the child table on the parentID and then use the Lookup() as described above to show the name in the outer gallery and the details of the child list in the inner gallery. 

I really commend you on following through on my suggestion.  The hard part is the proper design of the back end of the database.  The fun part is designing the user interface in creative ways to show your data.  Well Done Aharsh!

[aharsh]

Hi, @Drrickryp  - 

That's great - thank you very much!  You have taught me so much more than expected when jumping on with my question and the integrity of my data and stability of my future apps are all a tribute to your willingness to take time to walk me through the building blocks of planning your data.

I haven't tried what you recommend for combining lists for a gallery, but you've given me a great start (Nested Galleries, of course!) and I can lookup training from here.  I'm going to mark this as resolved, and once again thank you.  🙂