\name{asp.dbConnect}
\alias{asp.dbDisconnect}
\alias{asp.dbConnect}
\alias{asp.con}
\alias{asp.showConnection}
\alias{asp.lastCall}
\title{
  Create a connection between Asp and MySQL database containing 
  StatShop run data.
}
\description{
   The \code{asp.dbConnect} function creates a connection between Asp
   and a MySQL database containing the output from a StatShop run.  

   The \code{asp.dbDisconnect} function closes the database connection
   if it is still open.  This is done automatically when R exits.

   The \code{asp.showConnection} function shows the last command used to
   open a connection.
}
\usage{
asp.dbConnect(database, user, host="localhost", password="",
              driver=MySQL(force.reload=FALSE), ...)
asp.dbDisconnect()
asp.showConnection()
}

\arguments{
  \item{database}{String giving the name of the database containing
    the StatShop output.}
  \item{user}{String giving the user name of a user who has access to
    that output; often your NT login id.}
  \item{host}{Machine name for machine which contains the database.}
  \item{password}{Password if needed for connection.}
  \item{driver}{A DBIConnection object, defaults to using a RMySQL
    driver.} 
  \item{...}{Further arguments which are passed to \code{dbConnect}; not
  needed for MySQL connections, but reserved for future use.}
}
\details{
   The connection is mantained in a global variable called
   \code{asp.con} which is used as part of many of the other Asp
   function.  This function is basically a wrapper for the
   \code{dbConnect} function in the DBI package.

   A global variable \code{asp.lastCall} is use to record the last call
   to \code{asp.dbConnect}.  It is set to \code{NULL} by
   \code{asp.dbDisconnect}. 

}
\section{Side Effects}{
  A connection between R/S-Plus and an MySQL  server is 
  established.   The current implementation supports up to
  100 simultaneous connections.

  Sets the value of the global variable \code{asp.con} which maintains
  the connection.  If this connection closes, the \code{asp.dbConnect}
  function may need to be called again.

  Sets the value of the global variable \code{asp.lastCall} which tracks
  the last call used to open/close the database.
}
\references{
  See the Database Interface definition document
  \code{DBI.pdf} in the base directory of this package
  or \url{http://stat.bell-labs.com/RS-DBI}.
}
\seealso{
  \code{\link{MySQL}},\code{\link{daCapo}},
  \code{\link[DBI]{dbConnect}},\code{\link{listModels}},
  \code{\link{getChains}}, \code{\link{getCycles}},
  \code{\link{getAllParameters}}, \code{\link{getVariable}},
  \code{\link{asp.debugQueries}}
}
\examples{\dontrun{
## connect to a local database.
asp.dbConnect("mcmc_statistics_test","ralmond")
## connect to a remote database
asp.dbConnect("mcmc_statistics_test","junit",host="comet.research.ets.org")
## Close when finished
asp.dbDisconnect()
}
}
\keyword{database}