In this example, assume that an employee has repeated a class. To sequence two records with the same values for EMPNBR and CLSDTE, a third key field, DATE, is specified in record format CLSHST.
However, DATE cannot be specified in the next available key position (position 3) because JOBDTE and ACTDTE appear in that position for other formats. If DATE is specified in this position, the attributes of DATE are compared with the attributes of CLSHST and JOBHST, and the key definitions are rejected.
To obtain the sequencing necessary, specify *NONE before DATE, displacing DATE to key position 4.
The DATE field can be shown in position 4 as in Figure 1.
|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8 00010A R EMPMST PFILE(EMPMSTP) 00020A K EMPNBR 00030A* 00040A R CLSREG PFILE(CLSREGP) 00050A K EMPNBR 00060A K CLSDTE 00070A* 00080A R CLSHST PFILE(CLSHSTP) 00090A K EMPNBR 00100A K CLSDTE 00110A K *NONE 1 00120A K DATE 1 00130A* 00140A R JOBHST PFILE(JOBHSTP) 00150A K EMPNBR 00160A K *NONE 00170A K JOBDTE 00180A* 00190A R ACTHST PFILE(ACTHSTP) 00200A K EMPNBR 00210A K *NONE 00220A K ACTDTE A
| Record format | Key positions | |||
|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |
| EMPMST | EMPNBR | *NONE | *NONE | *NONE |
| CLSREG | EMPNBR | CLSDTE | *NONE | *NONE |
| CLSHST | EMPNBR | CLSDTE | *NONE | DATE |
| JOBHST | EMPNBR | *NONE | JOBDTE | *NONE |
| ACTHST | EMPNBR | *NONE | ACTDTE | *NONE |
Specifying DATE in key position 4 enables records from physical file CLSHSTP with identical values for EMPNBR and CLSDTE to be merged and sequenced according to the value for DATE.