You are probably familiar with using the OVRDBF command to access a specific member in a file with multiple members. Or maybe you use it to access all the members by using the MBR(*ALL) parameter. But did you know that the same functionality is available directly in RPG by using the EXTMBR keyword on your file definition? Here's an example:

The EXTMBR keyword accepts *FIRST, *ALL, or specific member names. By utilizing this functionality, you can get around the need for using the OVRDBF command.

Also, if you are using the EXTMBR('*ALL') option, then you should be aware of how the SETGT and SETLL opcodes function when processing a file with more than one member. Using the SETGT opcode as shown below will read the first record of the next file member in the file.

Conversely, by using the SETLL opcode, you can return to the bottom (last record) of the previous member, as shown below.

Although using these techniques can make processing files with multiple members much easier, there are a couple of things to keep in mind. For example, you will not be able to use the *hival with SETGT and expect that the next READ will fail (to exit from a loop, for instance). Also, unless you use the file information data structure (INFDS), you will not know which specific member is being processed.

Jeff Olen is a member of the AS/400 development team at Gauss Interprise, a content management software company located in Irvine, California. He can be reached by email at This email address is being protected from spambots. You need JavaScript enabled to view it..