search for clients with blank custom field

[snake]

I have a "mobile phone" custom field, and I want to search for all customers who left this blank.

Unfortunately using the advanced search doesn't seem to work, since leaving it blank just returns all customers.

 

[brian!]

then you'll probably going to need to use a SQL query - either directly via phpmyadmin etc, or inside a report.

although one problem you might run into is if this custom field was added after clients had already been created, e.g if you already had 1000 clients, and *then*  added this CCF to the setup, there would be no records in the relevant database table for those 1000 clients (unless they/you had updated those values)...

under those circumstances, you'd be querying for relevant field(s) that are either empty of don't exist.... if the CCF was setup before clients where created, then it should just be a straight if value is empty where condition... with relevant joins depending on what info you want to extract from the query (e.g client names etc)

[snake]

yea the field was added later on, when I started using an SMS module.

so the fields do not exist in the DB for most users.

I have noticed that most clients seem to have listed their main number as a mobile number.

So my goal is, to find out which clients do not have a mobile number.
check if the main profile phone  number starts with 07, which means it is a mobile number, and if so, copy it to mobile number custom field.