topic Re: Label Multiple Fields but Omit Null/Specific Value in Map Advice Community Questions

Label Multiple Fields but Omit Null/Specific Value

BenjaminSmith_McRobie2 — Mon, 23 Mar 2020 13:07:15 GMT

Hello All,

I am setting up manhole points with multiple labels (Manhole Number, Rim Elev, Inverts, etc.). I want to know if there is any possible way to write an expression that will omit/remove Null or specific values (such as "0"). I have screenshots below and a copy of my expression.

Thank you in advance!

Expression:

[ "MH#: " & [MH_ID] & vbNewLine & "RIM: " & [RIM_ELEV] & vbNewLine & "INV 1: " & [INV_1] & vbNewLine & "INV 2: " & [INV_2] & vbNewLine & "INV 3: " & [INV_3] & vbNewLine & "INV 4: " & [INV_4] ]

Re: Label Multiple Fields but Omit Null/Specific Value

JakeSkinner — Sun, 12 Dec 2021 10:27:06 GMT

Hey Benjamin,

I can provide you an example of this using Python:

def FindLabel ( [NAME], [FCC] ):
    if [FCC] == '0' or [FCC] == None:
        return [NAME]
    else:
        return [NAME] + '\n' + [FCC]‍‍‍‍‍

The statement is saying if the value of field FCC equals 0 or NULL, return only the value of field NAME. Else, return NAME and the FCC field values. Here is an example using Pro:

Re: Label Multiple Fields but Omit Null/Specific Value

JoshuaSharp-Heward — Mon, 23 Mar 2020 14:10:39 GMT

Hi,

I'm not familiar with VBScript, but this can be done relatively easily in Python, as long as you check the "Advanced" box in the Label expression window.

Example code:

def FindLabel ( [test], [test2] , [test4], [test3] 😞
test1, test2, test3, test4 = [test], [test2] , [test4], [test3] # assign variables for each of the input fields
returnstring = "" #empty string for label
for field in [test1, test2, test3, test4]: # looping through all input fields
if field is not None and field !="0": # checks field for your conditions, e.g. not null and not "0"
returnstring += field + '\n' #adds field values to return string if above condition met
return returnstring # returns label string

Writing it this way will work for any number of fields you have, assuming the logic is the same for each (excluding null values and "0"'s.

Hope this helps!

Re: Label Multiple Fields but Omit Null/Specific Value

BenjaminSmith_McRobie2 — Mon, 23 Mar 2020 17:28:40 GMT

All of your comments were extremely helpful, thank you!!

Re: Label Multiple Fields but Omit Null/Specific Value

WendyHarrison — Mon, 23 Mar 2020 18:11:29 GMT

Hi Benjamin,

Going through the labeling expression to do this will slow the labeling down, as each time it goes to label it runs the expression. The preferred way will be to narrow down what is labeled using a SQL query.

You can see in the screenshot below an example where there is a feature with a MyNumber value of 0 and one with a NULL value. The SQL query removes those and only the remaining features are labeled with the objectid field.

If you are not familiar with writing SQL queries please click the Help button on the dialog box and it will take you to the documentation - there are many examples included that will help you out with different scenarios.