First, run the Full DB that is in a zip.
Then you want to run all the update packs in Updates / 0.12.1_additions, starting with 394_corepatch_mangos_10546_to_10720.sql and 394_updatepack_mangos.sql (393 is already in the FullDB) and continuing to 400_updatepack_mangos.sql, always the corepatch first then the updatepack for each update number (394 corepatch, 394 updatepack, 395 corepatch, 395 updatepack, etc)
If you used character.sql included with mangos source, skip all the XXX_corepatch_characters_XXXXX_to_XXXXX.sql patches.
From there run any updates from the last corepatch_mangos (399, which has updates up to mangos revision 11242) to the latest update in mangos source / sql / updates.
Sorry there isn't any clear instructions on installing UDB anywhere.