not sure i understood what you need.
if what you want is update the text field from your DB where
your varchar field is something then try this
Update email_temp set temp_text="put your text in here"
where temp_name="name";
beware however that you have to code your text so that you don't get quotes to close your query too soon.
ex :
update email_temp set temp_text="hello "big boy", how are you?" where temp name="name";
this will not work, as mysql will think temp text="hello ".
use html_entities() or addslashes()
in PHP to prevent this.
read more in the string functions of the PHP manual.