library(RPostgreSQL)
#> Loading required package: DBI
library(RMySQL)
#> 
#> Attaching package: 'RMySQL'
#> The following object is masked from 'package:RPostgreSQL':
#> 
#>     dbApply
library(dbplyr)
library(tidyverse)

con = DBI::dbConnect(RSQLite::SQLite(), ":memory:")

t = tibble(
  A = sample(letters[1:5], 20, replace=T),
  B=sample(1:5, 20, replace=T),
  C = rnorm(20)
)

lf = lazy_frame(
  A = sample(letters[1:5], 20, replace=T),
  B=sample(1:5, 20, replace=T),
  C = rnorm(20)
)

copy_to(con, t, "test", overwrite = T)

dbListTables(con)
#> [1] "sqlite_stat1" "sqlite_stat4" "test"

t %>%
  nest(data = -A) %>%
  slice_sample(n=2) %>%
  unnest(cols = data)
#> # A tibble: 6 x 3
#>   A         B      C
#>   <chr> <int>  <dbl>
#> 1 c         5  0.233
#> 2 c         1  1.62 
#> 3 c         1 -0.373
#> 4 c         4  0.275
#> 5 c         3 -1.47 
#> 6 b         5 -0.958

lf %>%
  nest(data = -A) %>%
  slice_sample(n=2) %>%
  unnest(cols = data)
#> Error in UseMethod("nest"): no applicable method for 'nest' applied to an object of class "c('tbl_TestConnection', 'tbl_lazy', 'tbl')"

tdb = tbl(con, "test")
tdb %>%
  nest(data = -A)
#> Error in UseMethod("nest"): no applicable method for 'nest' applied to an object of class "c('tbl_SQLiteConnection', 'tbl_dbi', 'tbl_sql', 'tbl_lazy', 'tbl')"