Make a named list of tbl_dbi objects from a DBIConnection object
Source: R/utils.R
db_tables_to_list.RdA convenience function that returns a list of tbl_dbi
objects from a DBIConnection object, named as per the database table
names.
Arguments
- conn
A DBIConnection object, as returned by
dbConnect.
Details
See the introduction
to dbplyr vignette for getting started with databases and
dplyr.
Examples
# create an SQLite database in memory
con <- DBI::dbConnect(RSQLite::SQLite(), dbname = ":memory:")
# populate with tables
dplyr::copy_to(con, head(iris), "iris_head")
dplyr::copy_to(con, head(mtcars), "mtcars_head")
# create named list of tbl_dbi objects
db_tables <- db_tables_to_list(con)
# view tables
db_tables$iris_head
#> # Source: table<`iris_head`> [6 x 5]
#> # Database: sqlite 3.45.2 [:memory:]
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> <dbl> <dbl> <dbl> <dbl> <chr>
#> 1 5.1 3.5 1.4 0.2 setosa
#> 2 4.9 3 1.4 0.2 setosa
#> 3 4.7 3.2 1.3 0.2 setosa
#> 4 4.6 3.1 1.5 0.2 setosa
#> 5 5 3.6 1.4 0.2 setosa
#> 6 5.4 3.9 1.7 0.4 setosa
db_tables$mtcars_head
#> # Source: table<`mtcars_head`> [6 x 11]
#> # Database: sqlite 3.45.2 [:memory:]
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 21 6 160 110 3.9 2.62 16.5 0 1 4 4
#> 2 21 6 160 110 3.9 2.88 17.0 0 1 4 4
#> 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1
#> 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1
#> 5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2
#> 6 18.1 6 225 105 2.76 3.46 20.2 1 0 3 1
# to import to R, use dplyr::collect()
dplyr::collect(db_tables$iris_head)
#> # A tibble: 6 × 5
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> <dbl> <dbl> <dbl> <dbl> <chr>
#> 1 5.1 3.5 1.4 0.2 setosa
#> 2 4.9 3 1.4 0.2 setosa
#> 3 4.7 3.2 1.3 0.2 setosa
#> 4 4.6 3.1 1.5 0.2 setosa
#> 5 5 3.6 1.4 0.2 setosa
#> 6 5.4 3.9 1.7 0.4 setosa