R: Arrange rows by variables in a remote database table

arrange.tbl_lazy {dbplyr}

R Documentation

Arrange rows by variables in a remote database table

Description

Order rows of database tables by an expression involving its variables.

Usage

## S3 method for class 'tbl_lazy'
arrange(.data, ..., .by_group = FALSE)

Arguments

`.data`	A tbl. All main verbs are S3 generics and provide methods for `tbl_df()`, `dtplyr::tbl_dt()` and `dbplyr::tbl_dbi()`.
`...`	Comma separated list of unquoted variable names, or expressions involving variable names. Use `desc()` to sort a variable in descending order.
`.by_group`	If `TRUE`, will sort first by grouping variable. Applies to grouped data frames only.

Value

An object of the same class as .data.

Missing values

Compared to its sorting behaviour on local data, the arrange() method for most database tables sorts NA at the beginning unless wrapped with desc(). Users can override this behaviour by explicitly sorting on is.na(x).

Examples

library(dplyr)

dbplyr::memdb_frame(a = c(3, 4, 1, 2)) %>%
  arrange(a)

# NA sorted first
dbplyr::memdb_frame(a = c(3, 4, NA, 2)) %>%
  arrange(a)

# override by sorting on is.na() first
dbplyr::memdb_frame(a = c(3, 4, NA, 2)) %>%
  arrange(is.na(a), a)

[Package dbplyr version 1.4.2 Index]