When making massive changes to multiple templates within Expression Engine, we use a product called MySQL Studio available from Navicat in versions for Windows, Macintosh, and LINUX.  The product allows you to manipulate MySQL tables using a graphical user interface and provides security over SSH.  Beats the pants off of phpMyAdmin … in my humble opinion.

The query statement to change all templates to php_allow=“yes” is this:

update exp_templates set allow_php = replace(allow_php,’ n ‘,’ y ’ );

Likewise the query statement to change the input parse method to input is this:

update exp_templates set php_parse_location = replace(php_parse_location,’ o ‘,’ i ’ );

Of course, you don’t need Navicat to do this.  You can also implement this query by calling up MySQL using a command line.