Dragging a datasource column from the right pane into Writer inserts fields like the ones we use for serial letters. Surprisingly this does nothing in Calc. Work-around: Open the database file (there is a context-menu in the left pane) and add a query SELECT "Field_X" FROM "Table_Y". Then drag the whole query object from the left pane.
I forgot to mention that such a linked database.odb contains no data. It starts as a configuration file to link the office suite with some external data, for instance a directory of equally structured csv files. You may add queries (filtered and sorted record sets), reports (data dumped into Writer's layout) or forms (not useful with read-only sources).
There is also one special type of database which includes a whole portable database in the odb-file, but that's another story.
Once you leave the spreadsheet-paradigma and start using the whole software, it is possible to create simple repositories of csv data where one database connects to comma-separated files with .csv-suffix, another database connects to tab-separated files with .tab-suffix and a third one exposes all *.xyz-files with semicolons. I would perfer separated directories, but you can separate them by name-suffix as well.
Issue 1(quirk): Dragged columns don't tranfer into spreadsheets.
Issue 2 (missing feature): The driver does not support text tables separated by fixed field lenghts.
Issue 3(quirk): Character encoding can be fine-tuned after database creation (menu:Edit>Database>Properties...)
If you know how to utilize OOo-forms, you can create forms in ordinary external documents, not embedded in a particular database. Forms and subforms can be used to show related row sets from different databases. This should work well enough with small text-databases (<10,000 rows?).
I used to do this in OOo1.x with a tiny collection of dBase and spreadsheets. Seemingly the same technique works in recent versions, but I did not spend much time testing it.
Issue 4: In a read-only database it seems to be impossible to get the form's record set out of the form without writing macros.
Push the last button on toolbar "Form Navigation" while the focus is in a form or subform. A "secondary beamer" shows the displayed fields of the current form. Drag the row set into a document.