Shall I use mySQL to store value or format with function

I have a two separate tables that contain parts of user name (don't ask why)...

t1
---------------
firstName
lastName

t2
---------------
middleName
stage_firstName
stage_middleName
stage_lastName

So before I output the name I run it through a function that capitalizes First letter of Name and uses Stage name if provided.

It works OK, but I now have a case where I need to display multiple names. The question I have, is: shall I use mySQL to store properly formatted name when the user formats it initially, or keep the values in multiple tables and keep on using the function to format them. For some reason I think I can improve some performance by utilizing a single value from a tabl开发者_如何学Pythone, even if I add additional table column rather than keeping the fields separately in two separate tables and then parsing each name through this huge function.

Am I wrong with these assumptions?

And if, at some point, you need to extract the name and display/use it in a different format, you will need to then perform some kind of translation on the already formatted string.

You could write the formatting into the query though.