ENABLE Reference Manual

ENABLE ATTRIBUTES
TREE Attribute
To determine if potential join fields are appropriate, consider
the data values that the fields represent. Appropriate join
fields should represent the same data values. Although ENABLE
will allow you to link two boxes whose join fields represent
different kinds of data values, avoid doing this because an
application generated with such a link might not operate in the
manner you expect.
Figure 4-7 shows the record descriptions associated with the
boxes "employee-box" and "depends-box" discussed earlier in this
section.
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| |
| Record Description Associated Record Description Associated |
| With Employee-box With Depends-box |
|_______________________________________________________________|
| |
| RECORD employee. RECORD dependents. |
| FILE IS employ KEY-SEQUENCED. FILE IS depend RELATIVE. |
| 02 empno PIC 9(4). 02 empnum PIC 9(4). |
| 02 empname PIC X(30). 02 dependent-name PIC X(30). |
| 02 dept. 02 age PIC 9(2). |
| 04 regnum PIC 9(2). 02 sex PIC X. |
| 04 branchnum PIC 9(2). KEY "ep" IS empnum. |
| ... KEY "dn" IS dependent-name. |
| KEY 0 IS empno. KEY "ag" IS age. |
| KEY "en" IS empname. END |
| END |
| |
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Figure 4-7. Sample Record Descriptions
Notice that the "empno" field of "employee-box" has a data type
that is compatible with the "empnum" field of "depends-box."
The data types of these fields are compatible because both are
numeric integer. The names of these fields indicate that each
represents an employee identification number. If the files
described by the boxes contain data, you should examine this data
to determine if potential join fields represent the same data
values. Because both "empno" and "empnum" have compatible data
types and represent the same data values, these fields are
appropriate join fields for "employee-box" and "depends-box."
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