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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/spec-sql-read-table.R
\docType{data}
\name{spec_sql_read_table}
\alias{spec_sql_read_table}
\title{spec_sql_read_table}
\value{
\code{dbReadTable()} returns a data frame that contains the complete data
from the remote table, effectively the result of calling \code{\link[DBI:dbGetQuery]{DBI::dbGetQuery()}} with
\verb{SELECT * FROM <name>}.
An empty table is returned as a data frame with zero rows.
The presence of \link{rownames} depends on the \code{row.names} argument,
see \code{\link[DBI:rownames]{DBI::sqlColumnToRownames()}} for details:
\itemize{
\item If \code{FALSE} or \code{NULL}, the returned data frame doesn't have row names.
\item If \code{TRUE}, a column named "row_names" is converted to row names.
}
\itemize{
\item If \code{NA}, a column named "row_names" is converted to row names if it exists,
otherwise no translation occurs.
\item If a string, this specifies the name of the column in the remote table
that contains the row names.
}
The default is \code{row.names = FALSE}.
If the database supports identifiers with special characters,
the columns in the returned data frame are converted to valid R
identifiers
if the \code{check.names} argument is \code{TRUE},
If \code{check.names = FALSE}, the returned table has non-syntactic column names without quotes.
}
\description{
spec_sql_read_table
}
\section{Failure modes}{
An error is raised if the table does not exist.
An error is raised if \code{row.names} is \code{TRUE} and no "row_names" column exists,
An error is raised if \code{row.names} is set to a string and no corresponding column exists.
An error is raised when calling this method for a closed
or invalid connection.
An error is raised
if \code{name} cannot be processed with \code{\link[DBI:dbQuoteIdentifier]{DBI::dbQuoteIdentifier()}}
or if this results in a non-scalar.
Unsupported values for \code{row.names} and \code{check.names}
(non-scalars,
unsupported data types,
\code{NA} for \code{check.names})
also raise an error.
}
\section{Additional arguments}{
The following arguments are not part of the \code{dbReadTable()} generic
(to improve compatibility across backends)
but are part of the DBI specification:
\itemize{
\item \code{row.names} (default: \code{FALSE})
\item \code{check.names}
}
They must be provided as named arguments.
See the "Value" section for details on their usage.
}
\section{Specification}{
The \code{name} argument is processed as follows,
to support databases that allow non-syntactic names for their objects:
\itemize{
\item If an unquoted table name as string: \code{dbReadTable()} will do the
quoting,
perhaps by calling \code{dbQuoteIdentifier(conn, x = name)}
\item If the result of a call to \code{\link[DBI:dbQuoteIdentifier]{DBI::dbQuoteIdentifier()}}: no more quoting is done
}
}
\seealso{
Other sql specifications:
\code{\link{spec_sql_append_table}},
\code{\link{spec_sql_create_table}},
\code{\link{spec_sql_exists_table}},
\code{\link{spec_sql_list_fields}},
\code{\link{spec_sql_list_objects}},
\code{\link{spec_sql_list_tables}},
\code{\link{spec_sql_quote_identifier}},
\code{\link{spec_sql_quote_literal}},
\code{\link{spec_sql_quote_string}},
\code{\link{spec_sql_remove_table}},
\code{\link{spec_sql_unquote_identifier}},
\code{\link{spec_sql_write_table}}
}
\concept{sql specifications}
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