> dm_nycflights13(cycle = TRUE) %>% dm_examine_constraints() %>% as_tibble()
  table   kind  columns ref_table is_key problem                                
  <chr>   <chr> <keys>  <chr>     <lgl>  <chr>                                  
1 flights FK    dest    airports  FALSE  "242 entries (2.2%) of `flights$dest` ~
2 flights FK    tailnum planes    FALSE  "1640 entries (14.6%) of `flights$tail~
3 airlin~ PK    carrier <NA>      TRUE   ""                                     
4 airpor~ PK    faa     <NA>      TRUE   ""                                     
5 planes  PK    tailnum <NA>      TRUE   ""                                     
6 flights FK    carrier airlines  TRUE   ""                                     
7 flights FK    origin  airports  TRUE   ""                                     

