Need to create a countif formula to count repeated values in table. Is this possible/how?

Have you tried s Summary report on that field, and click the column twice to get it to sort duplicates at the top?

Doesn't a summary report by definition filter out duplicates, similar to a pivot table in excel? What I need are the values the summary report summarizes (e.g. John Smith appears on 12 records) to be reportable and dynamic to add new records meeting criteria.

A field to say the value in the field X appears Y amount of times in the whole table.

I can solve this by exporting the Summary Report to a new Table, but then I lose the ability for it to update automatically.

If you need an actual field, then yes you will need to have some daily process like a button to click  to merge in the unique values to a summary table.  I have not tested, but you may be able to make a saved table to table copy  where the values of the field are "merged' into a table where the Key field is the field in question, and have it thus add new records if needed.  Then a user would push that button from time to time to update the master table of unique fields.

The button would  used the urlroot() & "db/" &[_DBID_MY_TABLE_ID] & "?act=API_RunImport&ID=10" as part of its formula ..

I was hoping to apply this to multiple fields: Phone Number, Address, Email etc. to show me how many times I have different Customer Numbers (my key field, do not want to change). A countif gets me what I need in excel, but would have to operate out of a spreadsheet and do not want to do that. No solution for countif (within the same table) in Quick Base?

I think you'd be into scripting, as opposed to native QuickBase. There is no CountIF functionally aside from  relationship Summary fields.

What info do you need from me/my app in order to do this via scripting? Would love to see how this could be done to solve the issue we're trying to solve.

I suggest looking up Dan Diebolt on this forum. His contact info is on his Profile. He is all over this forum.

https://quickbase-community.intuit.com/users/513-dandiebolt_qb_pirate#

Post sample data and desired output report. I am stuck in Microsoft Azure Machine Learning presentation and they have no respect for the math and I am bored ...

Sample data below.
Don't want a report per say, but want to see when I select Customer Number - 1 there's a field (countif formula) that shows the exact same value in [Customer Phone] occurs 4 times in this table (countif in excel). If it was possible for the value in my countif formula once I click it to bring me to a report with all matching numbers, would be ideal. Then I need to apply this logic/formula to many other fields.

Customer Number Customer Name Customer Phone
1 John Smith 123-456-7890
2 Jane Does 123-456-7890
3 Gilbert Grape 123-456-7890
4 John Deere 321-456-7890
5 Darth Vader 123-456-7890

I am on a tablet so I can't do this now. But I think I will just use the Kaaggle Titanic dataset to better demonstrate how to perform a variety of summaries and grouping beyond countiff. Using underscore.js (which QuickBase uses) it is extremely easy to do this using GroupBy, CountBy, Index by and SortBy
methods.