dbReadTable: Convenience functions for importing/exporting DBMS tables

In RMySQL: Database Interface and 'MySQL' Driver for R

Convenience functions for importing/exporting DBMS tables

Description

These functions mimic their R/S-Plus counterpart get, assign, exists, remove, and objects, except that they generate code that gets remotely executed in a database engine.

Usage

## S4 method for signature 'MySQLConnection,character'
dbReadTable(conn, name, row.names, check.names = TRUE, ...)

## S4 method for signature 'MySQLConnection'
dbListTables(conn, ...)

## S4 method for signature 'MySQLConnection,character'
dbExistsTable(conn, name, ...)

## S4 method for signature 'MySQLConnection,character'
dbRemoveTable(conn, name, ...)

## S4 method for signature 'MySQLConnection,character'
dbListFields(conn, name, ...)

Arguments

conn	a MySQLConnection object, produced by dbConnect
name	a character string specifying a table name.
row.names	A string or an index specifying the column in the DBMS table to use as row.names in the output data.frame. Defaults to using the row_names column if present. Set to NULL to never use row names.
check.names	If TRUE, the default, column names will be converted to valid R identifiers.
...	Unused, needed for compatiblity with generic.

Value

A data.frame in the case of dbReadTable; otherwise a logical indicating whether the operation was successful.

Note

Note that the data.frame returned by dbReadTable only has primitive data, e.g., it does not coerce character data to factors.

Examples

if (mysqlHasDefault()) {
con <- dbConnect(RMySQL::MySQL(), dbname = "test")

# By default, row names are written in a column to row_names, and
# automatically read back into the row.names()
dbWriteTable(con, "mtcars", mtcars[1:5, ], overwrite = TRUE)
dbReadTable(con, "mtcars")
dbReadTable(con, "mtcars", row.names = NULL)
}

RMySQL documentation built on Sept. 11, 2024, 6:11 p.m.