RDDSETDEFAULT()
 Set or return the default RDD for the application
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 Syntax

     RDDSETDEFAULT([<cNewDefaultRDD>])
        --> cPreviousDefaultRDD

 Arguments

     <cNewDefaultRDD> is a character string, the name of the RDD that is
     to be made the new default RDD in the application.

 Returns

     RDDSETDEFAULT() returns a character string, cPreviousDefaultRDD, the
     name of the previous default driver.  The default driver is the driver
     that CA-Clipper uses if you do not explicitly specify an RDD with the
     VIA clause of the USE command.

 Description

     RDDSETDEFAULT() is an RDD function that sets or returns the name of the
     previous default RDD driver and, optionally, sets the current driver to
     the new RDD driver specified by cNewDefaultRDD.  If <cNewDefaultDriver>
     is not specified, the current default driver name is returned and
     continues to be the current default driver.

     This function replaces the DBSETDRIVER() function.

 Examples

     // If the default driver is not DBFNTX, make it the default

     IF ( RDDSETDEFAULT() != "DBFNTX" )
        cOldRdd := RDDSETDEFAULT( "DBFNTX" )
     ENDIF