HP Integrity NonStop J-Series - Manual (Page 64)

DEVELOPING A DATA BASE
Using DDL to Create a Record Description
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| |
| (2) Identifies a file name ("employee"); also indicates the |
| file type (KEY-SEQUENCED). |
| |
| (3) Names a field, "empnum." The PIC clause identifies the |
| size of this elementary field (four characters) and |
| indicates its data type (numeric). Note the two digits |
| to the left of the field name. These digits are called |
| level numbers. All fields have level numbers to |
| indicate their relationship to other fields. You can |
| select any digits from 1 to 50 for level numbers. |
| |
| Notice the HEADING clause that appears with this and |
| many other fields. Including such a clause provides |
| you with a method of supplying your own screen labels |
| when you use ENABLE to generate an application. |
| |
| (4) Names a field, "empname." The PIC clause identifies |
| the size of this elementary field (18 characters) and |
| indicates its data type (alphanumeric). |
| |
| (5) Names a field, "dept." Notice that this field does not |
| have a PIC clause. The absence of a PIC clause |
| indicates that the field is a group field. A group |
| field consists of all of the immediately following |
| elementary fields with lower level numbers. Be aware |
| of the way that DDL evaluates level numbers. For DDL, |
| a level number of 02 is higher than a level number of |
| 03. |
| |
| (6) Names a field, "regnum." The PIC clause identifies the |
| size (four characters) of this elementary field and |
| indicates its data type (numeric). Note that the level |
| number (04) associated with this field is lower than |
| the level number (02) associated with the group field |
| ("dept") of which "regnum" is a part. |
| |
| (7) Names a field, "salary." The PIC clause identifies the |
| size (six characters) of this elementary field and |
| indicates its data type (numeric). The symbol V in the |
| PIC clause indicates an implied decimal point. The |
| decimal point is not actually stored in the file. |
| |
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Figure 3-9. Sample DDL RECORD Statements (Continued)
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