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% file RODBC/man/sqlDrop.Rd
% copyright (C) 1999-2002 M. Lapsley
% copyright (C) 2002-2013 B. D. Ripley
%
\name{sqlDrop}
\alias{sqlDrop}
\alias{sqlClear}
\title{Deletion Operations on Tables in ODBC databases}
\description{
\code{sqlClear} deletes all the rows of the table \code{sqtable}.
\code{sqlDrop} removes the table \code{sqtable} (if permitted).
}
\usage{
sqlClear(channel, sqtable, errors = TRUE)
sqlDrop(channel, sqtable, errors = TRUE)
}
\arguments{
\item{channel}{connection object as returned by \code{\link{odbcConnect}}.}
\item{sqtable}{character string: a database table name accessible from the
connected DSN. This can be a \sQuote{dotted} name of the form
\code{\var{schema}.\var{table}}.}
\item{errors}{logical: if \code{TRUE} halt and display error, else
return \code{-1}.}
}
\details{
These submit \samp{TRUNCATE TABLE} and \samp{DROP TABLE} SQL queries
respectively.
\sQuote{Dotted} table names are allowed on systems that support them
but the existence of the table is not checked and so attempting these
operations on a non-existent table will give a low-level error. (This
can be suppressed by opening the connection with \code{interpretDot =
FALSE}.)
The default \sQuote{drop} behaviour in Oracle is to move the table to
the \sQuote{recycle bin}: use
\preformatted{
sqlQuery(channel, "PURGE recyclebin")
}
to empty the recycle bin.
The current user might not have privileges to allow these operations,
and Actual Technologies' Mac OS X SQLite driver has a bug causing them
silently to fail.
}
\value{
If \code{errors = FALSE}, a numeric value, invisibly.
Otherwise a character string or \code{invisible()}.
}
\seealso{
\code{\link{odbcConnect}}, \code{\link{sqlQuery}}, \code{\link{sqlFetch}},
\code{\link{sqlSave}}, \code{\link{sqlTables}}, \code{\link{odbcGetInfo}}
}
\author{
Michael Lapsley and Brian Ripley
}
\keyword{IO}
\keyword{database}
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