Data Definition Language (DDL) Reference Manual

DDL Compiler Commands
Data Definition Language (DDL) Reference Manual—529431-004
9-44
DDL
The specified DDL source code file must be an EDIT file, an unstructured file, or a
sequential device such as a terminal, a spooler, or a process. If the file exists but is not
one of these types, the DDL compiler issues an error message and does not open the
file.
Each DDL object translated to DDL source is written to the source code file in a
separate section that has the same name as the DDL structure it contains. You can
suppress the individual section headings with the SETSECTION command.
For dictionaries created from the DDL compiler, the DDL source is almost identical to
the original schema at the time the dictionary was created, and can be used to rebuild
a dictionary.
If the file \DALLAS.$DATA.SALES.DDLSRC already exists, the exclamation point in
the following line of code directs the DDL compiler to purge the contents of the file
before opening it. If the file does not exist, the DDL compiler creates a new file with the
specified name.
?DDL \dallas.$data.sales.ddlsrc !
In Example 9-20 on page 9-44, the compiler writes all the definitions and records from
the open dictionary to the DDL source code file, DDLSRC, first purging any data in that
file. Assume that the dictionary:
•
Does not contain Pathmaker information.
•
Contains one record, CUSTOMER, and all definitions necessary to build that
record.
The DDL source code file can be used to reconstruct the dictionary on another
subvolume:
Caution. Do not attempt to rebuild a dictionary installed by the Pathmaker product from DDL
source code; Pathmaker application design information will be lost.
Example 9-20. DDL Command (page 1 of 2)
DDL Input
29> DDL
!?DICT $data.sales
!?DDL ddlsrc !
!OUTPUT *.
Open existing dictionary.
Clear and open DDL source code file
Write all definitions and records to DDL source code file.