Introduction to DDL
Data Definition Language (DDL) Reference Manual — 426798-002
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Using DDL Definitions
file or directly from a terminal. In either case, the DDL compiler checks the syntax and
semantics of all statements and commands.
The DDL compiler translates the statements that define DDL objects into internal data
definition format. If a dictionary is open for read and write access, DDL writes the
compiled objects to the dictionary.
If output is requested, the DDL output generator retrieves the compiled object
definitions from the dictionary (if open), translates the definitions into the appropriate
source code, and writes the translated definitions to all open output files and devices.
Figure 1-1
is an overview of DDL.
Using DDL Definitions
You use DDL statements to define, modify, delete, and display data in a DDL
dictionary. You use DDL commands to create and open dictionaries and to generate
files containing FUP commands, data definition source code in different languages,
and report specifications. You can use DDL to perform the following functions:
•
Create a source schema
A DDL source schema is composed of DDL statements that define the DDL
objects. You can create a source schema in an EDIT file and submit the file to the
DDL compiler, or you can run DDL and enter the definitions interactively.
Figure 1-1. DDL Overview
VST001.vsd
Source
File
Dictionary
PASCAL
TAL
FORTRA
N
C
FUP
COBOL
TACL
DDL
Listing
Report
5> DDL
Compiler
Output
Generator
DDL