How can I query a custom text field for ONLY null values?

[Anon Anon]

I have a custom field called Acceptance Criteria, which is a text field.  I want to find all records where Acceptance Criteria is blank.

When I search for (C_AcceptanceCriteria = null) I get 0 results, though there are hundeds of records where the field is blank. 

Please help!  Client is requesting this simple report and I'm surprised I can't figure out how to handle this.

Note: we are using an older OnPrem version so I don't have the latest version of the system.

[Legacy User]

Jen, I use exactly that argument in one of my queries (we're SaaS, not on-prem) without issue so you may want to open a support case. There's one small tweak that you could try though I doubt it will make a difference- you no longer need the c_ in custom field names in your query strings, at least in SaaS and that's not a recent change. You could try that change and see what the results look like but I wouldn't really expect a change. Hope that helps.

[Anon Anon]

I'm having this exact problem. If you find a solution, please post the answer here.

[Legacy User]

Ryan, please do submit a case so we can look into this, as I can't reproduce any problem querying work items with null field values. 

[Anon Anon]

Turns at the trick for me was setting the query to match an empty string, not a null value. ( CustomString = "" ) worked, while (CustomString = null) did not.