The Moodle Database Activity is a lesser know activity type, but it can be useful for making simple submission systems, where a student submits an entry and other students can view it. 

A very basic example can be seen at:

A teacher sees more tab items than a student.

Teacher View
Student View

Submissions from teachers and students are available to students to view individually or as a list.

Using Poodll with the Database Activity

Poodll has a Poodll Database Field plugin. You should install this. NB This depends on the Poodll filter and is a part of the Poodll Media Package.

Once installed it will become available as an option under  "Fields."

From there choose the media type, video, audio , drawing or snapshot and give your field a name and description

Then visit each of the "templates" that are used to define the layout for the pages the student sees. Probably "Add template" , "single template" and "list template." There you should add your field. Moodle hopefully will add it for you, and you can just tweak it to suit your needs. 

To see more about the Moodle Database Activity Field. Visit: