combine two mysql fields and update a third one with result using php

Question

I have a database table that contain two fields "Categories" and "Tags"

i need to create a third field lets say called Keywords as the result of combining both categories and tags

so $Keywords = $tags." ".$categories;

can you help me please on how to achieve this

thanks

Answer 1

You can do this purely in SQL:

alter table Mytable add column Keywords varchar(255);
update Mytable set Keywords = concat(Categories, ' ', Tags);