/*
 * $Id: rdd.txt,v 1.7 2000/04/11 23:23:28 lculik Exp $
 */

/*
 * The following parts are Copyright of the individual authors.
 * www - http://www.harbour-project.org
 *
 * Copyright 1999 Luiz Rafael Culik <culik@sl.conex.net>
 *    DB*() documentation
 *    ORD*() documentation
 *    RDD*() documentation
 *
 * See doc/license.txt for licensing terms.
 *
 */


/*  $DOC$
 *  $FUNCNAME$
 *      RDDLIST()
 *  $CATEGORY$
 *      Database
 *  $ONELINER$
 *      Return an array of the available Replaceable Database Drivers
 *  $SYNTAX$
 *      RDDLIST([<nRDDType>]) --> aRDDList
 *  $ARGUMENTS$
 *     <nRDDType> is an integer that represents the type of the RDD you
 *   wish to list.  The constants RDT_FULL and RDT_TRANSFER represent the two
 *   types of RDDs currently available.
 *
 *   RDDType Summary
 *   컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴
 *   Constant       Value     Meaning
 *   컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴
 *   RDT_FULL       1         Full RDD implementation
 *   RDT_TRANSFER   2         Import/Export only driver
 *   컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴
 *
 *     RDT_FULL identifies full-featured RDDs that have all the capabilities
 *   associated with an RDD.
 *
 *     RDT_TRANSFER identifies RDDs of limited capability.  They can only
 *   transfer records between files.  You cannot use these limited RDD
 *   drivers to open a file in a work area.  The SDF and DELIM drivers are
 *   examples of this type of RDD.  They are only used in the implementation
 *   of APPEND FROM and COPY TO with SDF or DELIMITED files.
 *  $RETURNS$
 *     RDDLIST() returns a one-dimensional array of the RDD names registered
 *   with the application as <nRDDType>.
 *  $DESCRIPTION$
 *     RDDLIST() is an RDD function that returns a one-dimensional array that
 *   lists the available RDDs.
 *
 *     If you do not supply <nRDDType>, all available RDDs, regardless of type,
 *   are returned.
 *  $EXAMPLES$
 *     In this example RDDLIST() returns an array containing the
 *      character strings, "DBF", "SDF", "DELIM", "DBFCDX", and "DBFNTX":
 *
 *      REQUEST DBFCDX
 *
 *      .
 *      . < statements >
 *      .
 *
 *      aRDDs := RDDLIST()
 *
 *            // Returns {"DBF", SDF", "DELIM", "DBFCDX", "DBFNTX" }
 *
 *     In this example, RDDLIST() returns an array containing the
 *      character strings, "SDF" and "DELIM":
 *
 *      #include "rddsys.ch"
 *      .
 *      . < statements >
 *      .
 *      aImpExp := RDDLIST( RDT TRANSFER )
 *
 *  $TESTS$
 *
 *  $STATUS$
 *      R
 *  $COMPLIANCE$
 *
 *  $SEEALSO$
 *
 *  $INCLUDE$
 *      RDDSYS.CH
 *  $END$
 */

/*  $DOC$
 *  $FUNCNAME$
 *      RDDNAME()
 *  $CATEGORY$
 *      Database
 *  $ONELINER$
 *      Return the name of the currently active RDD
 *  $SYNTAX$
 *      RDDNAME() --> cRDDName
 *  $ARGUMENTS$
 *
 *  $RETURNS$
 *      Returns a character string, cRDDName, the registered name of the active
 *   RDD in the current or specified work area.
 *  $DESCRIPTION$
 *      RDDNAME() is an RDD function that returns a character string, cRDDName,
 *   the name of the active RDD in the current or specified work area.
 *
 *      You can specify a work area other than the currently active work area by
 *   aliasing the function.
 *  $EXAMPLES$
 *   USE Customer VIA "DBFNTX" NEW
 *   USE Sales    VIA "DBFCDX" NEW
 *
 *   ? RDDNAME()                          // Returns: DBFCDX
 *   ? Customer->( RDDNAME() )            // Returns: DBFNTX
 *   ? Sales->( RDDNAME() )               // Returns: DBFCDX
 *  $TESTS$
 *
 *  $STATUS$
 *      R
 *  $COMPLIANCE$
 *
 *  $SEEALSO$
 *      RDDLIST()
 *  $INCLUDE$
 *
 *  $END$
 */

/*  $DOC$
 *  $FUNCNAME$
 *      RDDSETDEFAULT()
 *  $CATEGORY$
 *      Database
 *  $ONELINER$
 *      Set or return the default RDD for the application
 *  $SYNTAX$
 *      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 HARBOUR 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
 *  $TESTS$
 *
 *  $STATUS$
 *      R
 *  $COMPLIANCE$
 *
 *  $SEEALSO$
 *      DBSETDRIVER()
 *  $INCLUDE$
 *
 *  $END$
 */


/*  $DOC$
 *  $FUNCNAME$
 *      __RDDSETDEFAULT()
 *  $CATEGORY$
 *      Database
 *  $ONELINER$
 *      Set or return the default RDD for the application
 *  $SYNTAX$
 *      __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 HARBOUR 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
 *  $TESTS$
 *
 *  $STATUS$
 *      R
 *  $COMPLIANCE$
 *
 *  $SEEALSO$
 *      DBSETDRIVER()
 *  $INCLUDE$
 *
 *  $END$
 */


