ANOMALIES UPLOADED ON 6-6-89


                                   ANOMALY 12.TXT


The following listing addresses two known anomalies when using
dBASE IV.  Use of these techniques will aid you in avoiding
anomalies that have been reported to our Software Support
Center.  There are also two usage-tips that may be used in order
to avoid further problems or misunderstandings when using the
dBASE IV product.  This report will be supplemented as new
information is received.  


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                                   ANOMALIES


Renaming a .DBO will cause "Procedure not found" error

     If a compiled .DBO file is renamed, the resultant file
     cannot be run.  Attempting to do so will return the error,
     "Procedure not found <new-name>.prs".  This fact should have
     been documented under the commands DO, COMPILE, and
     BUILD/DBLINK.  
     
     Since every program file becomes its own main procedure file
     and, in addition, when a file is compiled its name becomes
     compiled into the resultant .DBO, simply renaming a file
     will not change the references to the original filename in
     the .DBO file.  When the newly named file calls itself as a
     main procedure, this name is not the same as the filename of
     the main procedure compiled into the .DBO and the error is
     returned.
     
     Rather than renaming the .DBO file, the .PRG should be
     renamed prior to compiling.
     
===================================================================


CONVERT requires exclusive use of the file

     The CONVERT command requires that the file to be CONVERTed
     be used in EXCLUSIVE mode.  On page 4-4 of Networking with
     dBASE IV, CONVERT TO is correctly included in the list of
     commands requiring exclusive use.  This requirement is not
     documented on pages 2-59 or 60 of Language Reference nor 
     page 4-13 of Networking with dBASE IV.  
     
                                 USAGE-TIPS


@M will override other templates and functions

     The multiple choice picture function, @M, uses the literal
     values provided in the picture clause.  Therefore, The @M
     function will override any other picture or template
     function used in conjunction with it.
     
     EXAMPLE:
     
        STORE SPACE(20) TO Part_name
        @10,10 GET Part_name PICTURE "@M! Sofa, Bed, Chair"
     
     This example always returns the options as initial caps only
     instead of all caps.  Therefore, the enumerated data must be
     entered in all upper-case within the picture template if an
     upper-case template is desired.
     
===================================================================


SCAN...ENDSCAN and how records are moved within the construct

     The SCAN ... ENDSCAN construct is meant to handle record
     positioning itself.  It varies from the DO WHILE ... ENDDO
     construct in the sense that a
     DO WHILE is a looping mechanism, doing a certain operation
     multiple times. 
     DO ... WHILE does not automatically change the record
     pointer, where-as in a SCAN ... ENDSCAN construct, the
     record pointer update is handled internally.   
     
     SCAN                           DO WHILE .NOT. EOF()
     ...                                ...
                is equivalent to        SKIP
     ...                                ...
     ENDSCAN                        ENDDO
     
     Therefore, having the record pointer repositioned within the
     SCAN ... ENDSCAN construct may cause the record pointer to
     be improperly adjusted.
     
     EXAMPLE:
     
     USE <database name>
     SCAN While .T.
        LIST NEXT 10 <field name>
        IF EOF()
            GO TOP
        ENDIF
        CLEAR
     ENDSCAN
     
     The example above is intended to list 10 records at a time,
     doing consecutive passes through the database.  The first
     record of the database is only listed during the first pass
     through the file.  After the IF EOF() statement, GO TOP
     positions the record pointer at the top of the database, but
     since ENDSCAN internally changes the record pointer, a
     second SKIP is issued and the LIST command will start on the
     second record of the file.