DDS for physical and logical files

Join logical files in DDS

Join logical files combine different fields from more than one physical file into a single record. You must specify the JFILE keyword at the record level for join logical files.

Specify the entries in the following order to define a join logical file:

  1. File-level entries (optional)
  2. Record-level entries
  3. Join-level entries
  4. Field-level entries
  5. Key field-level entries (optional)
  6. Select/omit-field level entries (optional)

Because only one record format is allowed in a join logical file, specify these entries only once.

Figure 2 shows a join logical file coding example.

Figure 2. Join Logical File Coding Example

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A* Joins fields from two physical files into one record format
00020A          R RECORD1                   JFILE(PF1 PF2)
00030A          J                           JOIN(PF1 PF2)
00040A                                      JFLD(NAME NAME)
00050A            NAME                      JREF(1)
00060A            ADDR
00070A            PHONE
     A

You can find an explanation of file-, record-, join-, field-, key field-, and select/omit field-levels in the DDS Concepts information Describing data attributes using DDS topic.

Refer to the DDS Reference: Concepts information for rules to use when specifying keywords in DDS.


[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]