examine-constraints.md
In dm: Relational Data Models

output

Code
  dm() %>% dm_examine_constraints()
Message
  i No constraints defined.
Code
  dm_nycflights_small() %>% dm_examine_constraints()
Message
  ! Unsatisfied constraints:
Output
  * Table `flights`: foreign key `dest` into table `airports`: values of `flights$dest` not in `airports$faa`: SJU (30), BQN (6), STT (4), PSE (2)
  * Table `flights`: foreign key `tailnum` into table `planes`: values of `flights$tailnum` not in `planes$tailnum`: N725MQ (6), N537MQ (5), N722MQ (5), N730MQ (5), N736MQ (5), ...
Code
  dm_nycflights_small_cycle() %>% dm_examine_constraints()
Message
  ! Unsatisfied constraints:
Output
  * Table `flights`: foreign key `dest` into table `airports`: values of `flights$dest` not in `airports$faa`: SJU (30), BQN (6), STT (4), PSE (2)
  * Table `flights`: foreign key `tailnum` into table `planes`: values of `flights$tailnum` not in `planes$tailnum`: N725MQ (6), N537MQ (5), N722MQ (5), N730MQ (5), N736MQ (5), ...
Code
  dm_nycflights_small_cycle() %>% dm_select_tbl(-flights) %>%
    dm_examine_constraints()
Message
  i All constraints satisfied.
Code
  # n column
  dm_for_filter_w_cycle() %>% dm_examine_constraints()
Message
  i All constraints satisfied.

output as tibble

Code
  dm_nycflights_small_cycle() %>% dm_examine_constraints() %>% as_tibble()
Output
  # A tibble: 7 x 6
    table    kind  columns ref_table is_key problem                               
    <chr>    <chr> <keys>  <chr>     <lgl>  <chr>                                 
  1 flights  FK    dest    airports  FALSE  "values of `flights$dest` not in `air~
  2 flights  FK    tailnum planes    FALSE  "values of `flights$tailnum` not in `~
  3 airlines PK    carrier <NA>      TRUE   ""                                    
  4 airports PK    faa     <NA>      TRUE   ""                                    
  5 planes   PK    tailnum <NA>      TRUE   ""                                    
  6 flights  FK    carrier airlines  TRUE   ""                                    
  7 flights  FK    origin  airports  TRUE   ""

output for compound keys

Code
  bad_dm() %>% dm_examine_constraints()
Message
  ! Unsatisfied constraints:
Output
  * Table `tbl_2`: primary key `id`, `x`: has duplicate values: 3, E (2)
  * Table `tbl_3`: primary key `id`: has duplicate values: 4 (2)
  * Table `tbl_1`: foreign key `a`, `x` into table `tbl_2`: values of `tbl_1$a`, `tbl_1$x` not in `tbl_2$id`, `tbl_2$x`: 4, E (1), 5, F (1)
  * Table `tbl_1`: foreign key `b` into table `tbl_3`: values of `tbl_1$b` not in `tbl_3$id`: 1 (1), 5 (1)

Non-explicit PKs should be tested too

Code
  dm_for_card() %>% dm_examine_constraints()
Message
  ! Unsatisfied constraints:
Output
  * Table `dc_3`: unique key `b`, `a`: has duplicate values: e, 5 (2)
  * Table `dc_4`: foreign key `b`, `a` into table `dc_3`: values of `dc_4$b`, `dc_4$a` not in `dc_3$b`, `dc_3$a`: f, 6 (1)
  * Table `dc_6`: foreign key `c` into table `dc_1`: values of `dc_6$c` not in `dc_1$a`: 6 (1)

`dm_examine_constraints()` API

Code
  dm_examine_constraints(dm_test_obj(), progress = FALSE)
Condition
  Warning:
  The `progress` argument of `dm_examine_constraints()` is deprecated as of dm 1.0.0.
  i Please use the `.progress` argument instead.
Message
  i No constraints defined.
Code
  dm_examine_constraints(dm = dm_test_obj())
Condition
  Warning:
  The `dm` argument of `dm_examine_constraints()` is deprecated as of dm 1.0.0.
  i Please use the `.dm` argument instead.
Message
  i No constraints defined.

`dm_examine_constraints()` API (2)

Code
  dm_examine_constraints(dm_test_obj(), foo = "bar")
Condition
  Error in `dm_examine_constraints()`:
  ! `...` must be empty.
  x Problematic argument:
  * foo = "bar"