Hm.  New to InfoPath myself and don’t know what you mean by “template parts”.

You can submit data to a database if you design a form based on a database
connection.  Make sure you have all the latest Service Paks (SP).  Search the
help for “Design a form based on a database.” After the connection is
established, you should have a blank form with two boxes, 1 that says Enter
Query and another that says Enter Data or some such phrase.  In the Data
Source pane you will have two folders for fields:  Drag the Query ones to the
Query box on the form and Data to the Data.

If it’s a simple adding of data, you have to click on the “New Record”
button or “Insert” first before you can enter data in your controls that will
be excepted, then click submit after.  Grrr. MS Developers.

Hope that helps some
~Lori