Progress/400
Product Guide


Accessing Data from Multiple Members

An additional advantage of the QCMD command is that it allows you to change dynamically the physical file member against which you are working. To switch dynamically between file members, use the OS/400 Override Database File (OVRDBF) command. To execute this command remotely from a Progress client, use QCMD.

For example, assume that the Progress PRODEMO database STATE file has two members: one named STATE, the other EUROPE. The member named STATE contains the U.S. state information, and the EUROPE member holds similar information for European countries.

Suppose, for example, that you start a session as normal and execute this procedure:

FOR EACH state:
DISPLAY state. 

The output lists all of the U.S. states in the database file STATE, member STATE. To then run the same procedure but get a list of the European states, follow these steps:

  1. Enter this QCMD command to close the STATE file immediately:
  2. CREATE QCMD.
    ASSIGN cmd = "!CLOSE STATE".
    RELEASE. 
    

  3. Enter this QCMD command to access the data in the STATE, file EUROPE member:
  4. CREATE QCMD.
    ASSIGN cmd = "! OVRDBF FILE(STATE) MBR(EUROPE)".
    RELEASE. 
    

  5. Rerun the original Progress procedure:
  6. FOR EACH state:
    DISPLAY state. 
    

    The output will be the data from the EUROPE member. Use this technique to access data from multiple members.

    NOTE: Members must have the same data format.


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