odbcConnect {RODBC} | R Documentation |
Open connections to ODBC databases.
odbcConnect(dsn, uid = "", pwd = "", case = "nochange", believeNRows = TRUE) odbcDriverConnect(connection, case = "nochange", believeNRows = TRUE) odbcReConnect(channel, case, believeNRows)
dsn |
character string. A registered data source name. |
uid, pwd |
UID and password for authentication (if required). |
connection |
character string. See your ODBC documentation for the format. |
case |
Controls case changes for different RDBMS engines. |
channel |
RODBC connection object returned by odbcConnect . |
believeNRows |
logical. Is the number of rows returned by the ODBC connection believable? Not true for Oracle, apparently. |
odbcConnect
establishes a connection to the dsn, and
odbcDriverConnect
allows a more flexible specification via a
connection string. odbcConnect
uses the connection string
"DSN=dsn;UID=uid;PWD=pwd"
. See the examples for other
uses of connection strings.
For databases that translate table and column names the case must be
set as appropriate. Allowable values are "nochange"
,
"toupper"
and "tolower"
as well as the names of databases
where the behaviour is known to us (currently "mysql"
(which
maps to lower case on Windows but not on Linux),
"postgresql"
(lower), "oracle"
(upper) and
"msaccess"
) (nochange).
Function odbcReConnect
re-connects to a database using the
settings of an existing (and presumably now closed) channel object.
Arguments case
and believeNRows
are taken from the
object, but can be overridden by supplying those arguments.
A non-negative
integer which is used as handle if no error occurred, -1 otherwise.
A successful return has class "RODBC"
, and attribute
"connection.string"
giving the full ODBC connection string.
Michael Lapsley, Brian Ripley
odbcClose
, sqlQuery
, odbcGetInfo
# MySQL channel <- odbcConnect("test", uid="ripley", pwd="secret") # PostgreSQL channel <- odbcConnect("pg", uid="ripley", pwd="secret", case="postgresql") # re-connection odbcCloseAll() channel <- odbcReConnect(channel) # must re-assign as the data may well change