Moodle has a simple built-in database activity that lets students submit data into a database. No coding is required. Instructors set up forms that students use to submit data. For example, if every student in a class needs to submit information about a web page they found, the database could collect the title of the web page, the url, and a description of the page. Other students could see the list of collected pages and search for specific entries.
More information available at Moodle's Database activity page.
The database activity uses a templating system for data entry, list display, and single item display. In some cases, the rich-text editor tries to autocomplete HTML tags on more complex templates. If you are having trouble, try going to your profile (by clicking on your name in the top right of the Moodle page) → Settings → Edit Profile → When Editing Text pulldown → Use Standard Web forms. You will probably want to switch it back to "Use HTML Editor" once you are done with the template editing.