INstead of having to pre-define a number of related columns in Sheets (e.g.,Parent1,Parent2, Parent3) to "drive the match multiple process, could it be possible to simply have comma separated values in a single Parent column produce the same result?
It would avoid having to predefine an unknown number of columns and simply autoexpand to match the max number of values in any one column … maybe?
You don’t don’t have to predefine the number of columns. All you need is a relation column and a lookup column to the sheet that contains your list of values. Then create a relation column using the lookup column.
I’m not sure we’re understanding each other on this one.
I’m talking about the situation in which the source sheet has multiple sequentially named columns which are grouped by Glide into a single “many” relationship column.
In that case, unless I’m mistaken, the columns are predefined in the sheet and adding more relation options would mean inserting new sequentially columns into the backend sheet.
It seems it might be easier to source the relations column in the Glide datasheet from a single column in the Google sheet and simply extrapolate the comma separated values in the Google sheet into the relations column in the Glide sheet.
I completely understand what your are saying. You can either predefine columns (1, 2, 3, etc.) to make an array of values appear as one column. You can also use the combination of a multiple Relation column and Lookup column to build and array of values. The advantage of the Relation/Lookup method is that it builds an array of values from multiple ROWS instead of multiple COLUMNS. This allows the Lookup column to dynamically contain as many values as you need without the need to modify the sheet to add more values. The lookup column can be used when building other relation columns. I’ve done this several times and it works great. If you had a list of 1000 values, you could store then in a sheet as 1000 rows instead of 1000 columns, the load them into a single lookup column as 1000 values.
Ah. Well, now I understand you!
Thanks for taking the time to explain further!
Could you please elaborate the required steps with an example? Thanks
I’ll have to try and sort out how to experiment with this approach.
It sounds great … but I’m not quite sure how it lets different items have different combinations of relations with values from the lookup column.
I’ll try to come up with an example in the next few days. In the meantime, if you have a sample sheet with a short description of what you are trying to do, it would help me to build an example that relates to your situation.
Wow! Thanks very much. I’ll put together an example sheet a little later today.
@Jeff_Hager is this how you create things like tags? (Which unlike categories that are usually fixed, the user just adds as many as they like)
@chrishoward yes, this is at great way to do tags. The number of tags could be virtually unlimited. I’m not sure what you would do with an array of tags though, since you wouldn’t be able display them in a component. You can however display the relation as a list of tags, then click into the tag where you can then further use relations an lookups to find other people or items with the same tag.
I think the ability to combine relation and lookup columns to get an array of values is one of the most powerful features of glide that I think many people don’t realize they can do. Also being able to use an array of values for many to many relations. You can use an array on either side of a relation column. One thing I like to play with, is using relation/lookup/relation combinations.
Nice, @Jeff_Hager! I think I’ve got that working.
Be good if I could skip the “Add tag” button and just type it in a text entry component and have that populate the Tags sheet. But Glide seems to only allow pushing data to the sheet the edit screen is created for. 
Yeah, that would be pretty cool. Yes, I think each screen is tied to a specific sheet. I suppose you could get creative with formulas and maybe do something with split and transpose to populate a separate sheet. That or use a script to do something similar.
I know I’ve been putting this off, but I was really hoping somebody with give me some data to work with. It’s time consuming and I have a ton of test apps in my account.
Anyway, I didn’t forget about you. There is an example here that describes the process. It’s a little bit more complicated of an example, but I am using the Relation to Lookup to Relation method here.