4.3.2 A Simple Inquiry

Construct a function to display records from a file.

Files Involved

Physical file CUSMST (customer master file)

RDML Program - Version 1

    GROUP_BY   NAME(#CUSTOMER) FIELDS(#CUSTNO #NAME #ADDL1 

               #ADDL2 #ADDL3)

    BEGIN_LOOP

L10 REQUEST    FIELD(#CUSTNO)

    FETCH      FIELDS(#CUSTOMER) FROM_FILE(CUSMST) 

               WITH_KEY(#CUSTNO) NOT_FOUND(L10) 

               ISSUE_MSG(*YES)

    DISPLAY    FIELDS(#CUSTOMER)

    END_LOOP

 

RDML Program - Version 2

    GROUP_BY   NAME(#CUSTOMER) FIELDS(#CUSTNO #NAME #ADDL1 

               #ADDL2 #ADDL3)

    BEGIN_LOOP

    REQUEST    FIELD(#CUSTNO)

    FETCH      FIELDS(#CUSTOMER) FROM_FILE(CUSMST) 

               WITH_KEY(#CUSTNO)

       IF_STATUS  IS(*OKAY)

       DISPLAY    FIELDS(#CUSTOMER)

       ELSE

       MESSAGE    MSGTXT('No customer exists with this number')

       ENDIF

    END_LOOP

 

Points to Note:

• Both versions keep doing inquiries until the EXIT or MENU function key is used (BEGIN_LOOP and END_LOOP commands).

• The EXIT and MENU function keys are enabled on the REQUEST and DISPLAY screens by default. If either key is used the function will end.

• The first version uses the NOT_FOUND and ISSUE_MSG parameters of the FETCH command to automatically cause a "not found" message to be issued and then to return control to the request command.

• The second version uses the IF_STATUS command to check if the record was found. If it was it is displayed, else a message is issued that will appear on line 22/24 of the REQUEST screen