select.tbl_lazy: Subset, rename, and reorder columns using their names

In dbplyr: A 'dplyr' Back End for Databases

Subset, rename, and reorder columns using their names

Description

These are methods for the dplyr select(), rename(), and relocate() generics. They generate the SELECT clause of the SQL query.

These functions do not support predicate functions, i.e. you can not use where(is.numeric) to select all numeric variables.

Usage

## S3 method for class 'tbl_lazy'
select(.data, ...)

## S3 method for class 'tbl_lazy'
rename(.data, ...)

## S3 method for class 'tbl_lazy'
rename_with(.data, .fn, .cols = everything(), ...)

## S3 method for class 'tbl_lazy'
relocate(.data, ..., .before = NULL, .after = NULL)

Arguments

.data	A lazy data frame backed by a database query.
...	<data-masking> Variables, or functions of variables. Use desc() to sort a variable in descending order.
.fn	A function used to transform the selected .cols. Should return a character vector the same length as the input.
.cols	<tidy-select> Columns to rename; defaults to all columns.
.before, .after	<tidy-select> Destination of columns selected by .... Supplying neither will move columns to the left-hand side; specifying both is an error.

Examples

library(dplyr, warn.conflicts = FALSE)

db <- memdb_frame(x = 1, y = 2, z = 3)
db %>% select(-y) %>% show_query()
db %>% relocate(z) %>% show_query()
db %>% rename(first = x, last = z) %>% show_query()

dbplyr documentation built on May 29, 2024, 6:19 a.m.