foo.sql

-- Select all media galleries and find all images in there that follow the path structure: public://images/%/%/%/% 
SELECT n.nid, fmi.field_media_items_fid, file.uri
FROM 
  node n
INNER JOIN
  field_data_field_media_items fmi ON fmi.entity_id = n.nid
INNER JOIN
  file_managed file ON file.fid = fmi.field_media_items_fid
WHERE
  n.type = 'media_gallery'
  AND
  file.uri LIKE 'public://images/%/%/%/%';