Can you use a dropdown list in a select formula

[Jpaulsen]

Hello, 

I am kinda lost here. Here is what I am trying to do. I want to use a select formula based on values entered in a form, then look for values that match it. I like to either use dropdown list or user input value. 

Here's my Example. 

Form

Type of Filter (Input value**) **Engine Oil Filter 

Part Number (Input Value**) **Part Number 

Formula I been trying to get to work is:

Select(ledcor[unit],

( [Part Number] = [type of Filter]), True) But it doesn't take the input value **Engine Oil Filter from Type of Filter. It looks for a column that is named Types of Filters. 

If I change [Type of Filter] to [Engine Oil Filter] it works. but I have more then one type of filters I want look for. In the main sheet it's broken down in to different types. Example "Engine oil Filter, Hydraulic Filter, Transmission Filter... etc. Now is excel I am able to do this but the formula does not transfer to AppSheet. 

[WillowMobileSys]

First, for the expression to work, your Part Number row must have a column that identifies the "Type of Filter".

What you are referring to, if I understand correctly, is what's known as a Dependent Dropdown

Assuming the above, you would insert into the Valid_If a FILTER() expression to provide a list of parts.  You mention that "I have more then one type of filters I want look for" .  I'll assume this means to choose multiple filter types to show a list of parts.

Do these things:

1)  Make the "Type of Filter" column an EnumList to allow for choosing more than one.

2)  Set the "Valid_If" property, to set the dropdown, of the Part Number column like this:

IF(ISBLANK([Type of Filter),
   Parts Table[Row Key Column],
   FILTER("Part Table", IN([Part Filter Type], [_THISROW].[Type of Filter])
)

NOTE: you will need to change the table and column values to those of your app.

Description of expression - If no [Type of Filter] is selected, the expression will show all parts in the dropdown.  Once a [Type of Filter] has been chosen, the dropdown list will adjust and filter the parts based on one or more chosen [Type of Filter].

I hope this helps!

[Jpaulsen]

Thank you for you reply. 

So the table is called Equipment Info. Each Unit as several type of filters it use. Each type of filter has its specific part number under each type of filter it requires. Screen shot for you. I unclear [Row Key Column] 

[WillowMobileSys]

Ok, understood.  You want to show all of the values within the column of the chosen filter type.  Correct?

Your expression will need to be more like this:

IFS(
     [Type of Filter] = "Engine Oil Filter",
          UNIQUE(Equipment[Engine Oil Filter]),

     [Type of Filter] = "Fuel Filter",
          UNIQUE(Equipment[Fuel Filter]),

     [Type of Filter] = "Water Separator Filter",
          UNIQUE(Equipment[Water Separator Filter]),

     ...

)

[Jpaulsen]

So would that Formula go into the main formula or as. a Data Validity Value if: or somewhere else. Or would that be part of the select formula, and if so would that go before the select formula or after? 

Thank you again for your help. 

[WillowMobileSys]

Valid_If property of the Part Number column.

[Jpaulsen]

That works great for filtering the type of filters with part number. Love it!!!! Now how do I  also get the unit(s) show on the selected two values?  Thanks in advance.