In xenForo I set up the same field as a dropdown selection, with yes or no.
I (wrongly) assumed that in xenForo, this field was stored in xf_user_field_value, creating a row with the user_id, field_id, and field_value when the value was set.
Therefore I ran an SQL query to update this table and set the field_value to yes where vbulletin>userid_customfield = 1, else set the field_value to no. I thought this had worked.
A quick check of the batch update users function where this field is 'set to yes', brought back roughly the right amount of users that were set in vb, the same with 'set to no'
Now I read that this custom field information also stored in the xf_user_profile table itself too.
Now I'm a little out of my depth.
I still have access to the old vbulletin database.
What would the relevant SQL query be to update our xen installation, setting this new dropdown field to "yes" where it is checked in the old database, otherwise set it to "no".
It's a field that's also displayed on our postbit too, so that's how I noticed that it wasn't set for alot of people, as it wasn't showing up.