Django data migrations to merge database table fields
##Problem Initially, users table have first_name and last_name fields. After deploying the project on production, we realized that not every user in the system has a last_name. This results in enough empty rows for last_name. Now the solution is, merge first_name and last_name fields into one field that is full_name. How will you do this without losing any data on production?
###BE EXTRA CAREFUL ON PRODUCTION!!!