dbplyr: collapse.tbl_sql – R documentation

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collapse.tbl_sql

Compute results of a query

Description

These are methods for the dplyr generics collapse(), compute(), and collect(). collapse() creates a subquery, compute() stores the results in a remote table, and collect() executes the query and downloads the data into R.

Usage

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

## S3 method for class 'tbl_sql'
compute(
  x,
  name = unique_table_name(),
  temporary = TRUE,
  unique_indexes = list(),
  indexes = list(),
  analyze = TRUE,
  ...
)

## S3 method for class 'tbl_sql'
collect(x, ..., n = Inf, warn_incomplete = TRUE)

Arguments

`x`	A lazy data frame backed by a database query.
`...`	other parameters passed to methods.
`name`	Table name in remote database.
`temporary`	Should the table be temporary (`TRUE`, the default`) or persistent (`FALSE')?
`unique_indexes`	a list of character vectors. Each element of the list will create a new unique index over the specified column(s). Duplicate rows will result in failure.
`indexes`	a list of character vectors. Each element of the list will create a new index.
`analyze`	if `TRUE` (the default), will automatically ANALYZE the new table so that the query optimiser has useful information.
`n`	Number of rows to fetch. Defaults to `Inf`, meaning all rows.
`warn_incomplete`	Warn if `n` is less than the number of result rows?

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) %>% collect()

dbplyr

A 'dplyr' Back End for Databases

v2.1.1

MIT + file LICENSE

Authors

Hadley Wickham [aut, cre], Maximilian Girlich [aut], Edgar Ruiz [aut], RStudio [cph, fnd]

Initial release