dbConnect {Rdbi}R Documentation

Connect to a database


dbConnect is a generic function that, when evoked with a valid database class, will return a connection object.


dbConnect(dbObj, ...)


dbObj A database class object.
... An argument list specifying connection options.


Each package that sub-classes Rdbi must provide a dbConnect function. The first argument of the dbConnect function is an object whose class determines which dbConnect method is actually called. For example, the Rdbi.PgSQL package provides a function PgSQL() that returns an object of class c("PgSQL", "Rdbi"). Therefore the call dbConnect(PgSQL(), ...) will invoke the method dbConnect.PgSQL. Rdbi arranges for the specific package to be loaded via the autoload mechanism. In this example, Rdbi.PgSQL is autoloaded when PgSQL is called.


A database connection object that inherits from "Rdbi.conn". Additionally, the connection object should possess two attributes required to reopen the connection from the object. The "library.call" contains a call or expression that will load the library necessary to support the connection object. The "connect.call" attribute should contain the call that created the connection object. Also, it is very convenient to arrange for low-level connection resources to be freed when the R connection object is garbage collected. See the Rdbi.PgSQL C code for an example.


Timothy H. Keitt



See Also

dbDisconnect, dbReconnect, methods, class, match.call

[Package Rdbi version 1.0.4 Index]