I have imported hundreds of contacts having a custom field called "Langue" in set "ocsr" and having two possible values, 'F' and 'N'. I want to transfer this information into the field preferred language, with values 'fr_FR' and 'nl_NL'.
I suppose it is possible to do it in one Mysql operation, but I don't find where the custom field value is stored:
update civicrm_contact set preferred_language = 'fr_FR' where ... ocsr::Langue ... = 'F'
Any hint would be appreciated.