HP Integrity NonStop J-Series - Manual (Page 62)

DEVELOPING A DATA BASE
Using DDL to Create a Record Description
After you choose the key fields for your files, you are ready to
use the Data Definition Language (DDL) to describe your data
base.
DESCRIBING A DATA BASE
Before you can use ENABLE to generate an application, you must
use DDL to describe each of the files in your data base. When
you use DDL, you create a data dictionary.
A data dictionary is a set of files that documents the structure
of the data base. The dictionary documents the structure of each
file with a record description that you create. When you create
a record description, you can provide the following information:
• Field names
• The type of data (either alphanumeric, alphabetic, or numeric)
that a field represents
• The size of a field
• A label for the field that can be used by both ENABLE and
ENFORM
• The name of a file whose organization is described by the
record description
• The structure (key-sequenced, relative, entry-sequenced, or
unstructured) of a file that the record description describes
• Key fields
When you use DDL to create the record description and the
dictionary, you can also produce File Utility Program (FUP)
source code with which you can create the data base file.
Using DDL to Create a Record Description
To create a record description, you use the DDL RECORD statement.
Although you can use DDL interactively, the recommended procedure
is to enter the DDL source code (in this case, the DDL RECORD
statement) in an edit-type file.
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