R/ODBCDriver.R

In teramonagi/RODBCDBI: Provides Access to Databases Through the ODBC Interface

#' ODBCDriver and methods.
#'
#' An ODBC driver implementing the R database (DBI) API.
#' This class should always be initialized with the \code{ODBC()} function.
#' It returns an object that allows you to connect to ODBC.
#'
#' @export
#' @keywords internal
setClass("ODBCDriver", contains = "DBIDriver")

#' Generate an object of ODBCDriver class
#'
#' This driver is for implementing the R database (DBI) API.
#' This class should always be initialized with the \code{ODBC()} function.
#' ODBC driver does nothing for ODBC connection. It just exists for S4 class compatibility with DBI package.
#'
#' @export
#' @examples
#' \dontrun{
#' driver <- RODBCDBI::ODBC()
#' # Connect to a ODBC data source
#' con <- dbConnect(driver, dsn="test")
#' # Always cleanup by disconnecting the database
#' #' dbDisconnect(con)
#' }
ODBC <- function() {new("ODBCDriver")}


#' @rdname ODBCDriver-class
#' @export
setMethod("dbUnloadDriver", "ODBCDriver", function(drv, ...) {TRUE})

#' Connect/disconnect to a ODBC data source
#'
#' These methods are straight-forward implementations of the corresponding generic functions.
#'
#' @param drv an object of class ODBCDriver
#' @param dsn Data source name you defined by ODBC data source administrator tool.
#' @param user User name to connect as.
#' @param password Password to be used if the DSN demands password authentication.
#' @param connection Connection string to use to connect to the ODBC database server (as per \code{odbcDriverConnect}, e.g. 'driver={SQL Server};server=mysqlhost;database=mydbname;trusted_connection=true')
#' @param ... Other parameters passed on to methods
#' @export
#' @examples
#' \dontrun{
#' # Connect to a ODBC data source
#' con <- dbConnect(RODBCDBI::ODBC(), dsn="test")
#' # or using a connection string
#' con <- dbConnect(RODBCDBI::ODBC(),
#'   connection="driver={SQL Server};server=mysqlhost;
#'   database=mydbname;trusted_connection=true")
#' # Always cleanup by disconnecting the database
#' #' dbDisconnect(con)
#' }
setMethod(
  "dbConnect",
  "ODBCDriver",
  function(drv, dsn, user = NULL, password = NULL, connection, ...){
    uid <- if(is.null(user)) "" else user
    pwd <- if(is.null(password)) "" else password
    if (missing(dsn) && !missing(connection))
        con <- odbcDriverConnect(connection, ...)
    else
        con <- odbcConnect(dsn, uid, pwd, ...)
    new("ODBCConnection", odbc=con)
  }
)

#' @rdname ODBCDriver-class
#' @export
setMethod("dbIsValid", "ODBCDriver", function(dbObj) {TRUE})

#' Get ODBCDriver metadata.
#'
#' Nothing to do for ODBCDriver case
#'
#' @rdname ODBCDriver-class
#' @export
setMethod("dbGetInfo", "ODBCDriver", function(dbObj, ...) {NULL})