dbReadTable,MySQLConnection,character-method
Convenience functions for importing/exporting DBMS tables
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 MySQLConnection,character
dbReadTable(conn, name, row.names, check.names = TRUE, ...)# S4 method for MySQLConnection
dbListTables(conn, ...)
# S4 method for MySQLConnection,character
dbExistsTable(conn, name, ...)
# S4 method for MySQLConnection,character
dbRemoveTable(conn, name, ...)
# S4 method for MySQLConnection,character
dbListFields(conn, name, ...)
Arguments
- conn
a
'>MySQLConnection
object, produced bydbConnect
- 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 therow_names
column if present. Set toNULL
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
# NOT RUN {
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)
}
# }