Collapse a query into a subquery

collapse() forces computation of a lazy query by wrapping it in a subquery. This is not generally needed, but can be useful if you need to work around database/dbplyr limitations.

Usage

# S3 method for class 'tbl_sql'
collapse(x, ...)

Arguments

x

A lazy data frame backed by a database query.

...

Ignored.

Examples

library(dplyr, warn.conflicts = FALSE)

db <- memdb_frame(a = c(3, 4, 1, 2), b = c(5, 1, 2, NA))
db |> filter(a <= 2) |> show_query()
#> <SQL>
#> SELECT `dbplyr_tmp_BVkzIbwPcL`.*
#> FROM `dbplyr_tmp_BVkzIbwPcL`
#> WHERE (`a` <= 2.0)
db |> filter(a <= 2) |> collapse() |> show_query()
#> <SQL>
#> SELECT `dbplyr_tmp_BVkzIbwPcL`.*
#> FROM `dbplyr_tmp_BVkzIbwPcL`
#> WHERE (`a` <= 2.0)