SOQL exclude records with blank values on Multi-select picklist fields

Question

I have field Application_type__c on lead object which is multiselect picklist. I want to exclude records where picklist value is No application' or 'Global Markets or Blank.

My query is

Select Id, Name,Application_type__c , Lead_Age_Days__c from Lead 
                                where isConverted = false
                                and (
                                    (LeadSource = 'Client-Portal-Lead' and Client_Portal_Stage__c = 'Page2 Completed') 
                                    or (LeadSource = 'Client-Portal-Lead-Ar' and Client_Portal_Stage__c = 'Page2 Completed') 
                                    or (LeadSource = 'Manual entry' and Client_Portal_Stage__c = null)
                                    ) 
                                and Entity__c = 'Abu Dhabi' 
                                and CST_Owner__c = null 
                                and Application_type__c excludes ('No application','Global Markets') 
                                ORDER BY CreatedDate ASC

I get required result + Record where this field is blank or NULL.

If I change

Application_type__c excludes ('No application','Global Markets') to

Application_type__c excludes ('No application','Global Markets','') 

It gives results with No application as well.

How can I exclude record where this field is NULL or blank

Answer 1

Since Application_type__c is apparently a multi-select picklist which are also of Type string, it would seem you'd want to specify

Application_type__c excludes ('No application','Global Markets') AND !Application_type__c.isEmpty()

string.isEmpty() tests for both empty strings and strings with a value of null.