relational-duckdb.md
In duckplyr: A 'DuckDB'-Backed Version of 'dplyr'

duckdb_rel_from_df()

Code
  data.frame(a = vctrs::new_vctr(1:3)) %>% duckdb_rel_from_df()
Condition
  Error:
  ! Can't convert columns of class <vctrs_vctr> to relational. Affected column: `a`.

duckdb_rel_from_df() error call

Code
  as_duckdb_tibble(data.frame(a = factor(letters)))
Condition
  Error in `as_duckdb_tibble()`:
  ! Can't convert columns of class <factor> to relational. Affected column: `a`.

rel_aggregate()

Code
  grouped %>% rel_to_df(prudence = "lavish") %>% arrange(species)
Output
  # A duckplyr data frame: 2 variables
    species   mean_bill_length_mm
    <chr>                   <dbl>
  1 Adelie                   38.8
  2 Chinstrap                48.8
  3 Gentoo                   47.5
Code
  ungrouped %>% rel_to_df(prudence = "lavish")
Output
  # A duckplyr data frame: 1 variable
    mean_bill_length_mm
                  <dbl>
  1                43.9

duckdb_rel_from_df() uses materialized results

Code
  duckdb_rel_from_df(df)
Message
  DuckDB Relation: 
  ---------------------
  --- Relation Tree ---
  ---------------------
  Projection [a as a]
    Order [___row_number ASC]
      Filter [(a = 1.0)]
        Projection [a as a, row_number() OVER () as ___row_number]
          r_dataframe_scan(0xdeadbeef)

  ---------------------
  -- Result Columns  --
  ---------------------
  - a (DOUBLE)

Code
  nrow(df)
Output
  [1] 1

Code
  duckdb_rel_from_df(df)
Message
  DuckDB Relation: 
  ---------------------
  --- Relation Tree ---
  ---------------------
  r_dataframe_scan(0xdeadbeef)

  ---------------------
  -- Result Columns  --
  ---------------------
  - a (DOUBLE)