Generates DTD output based on a SELECT statement. The content of the DTD document is directly deduced from the table definitions in the repository.
The resulting DTD output is a string. Only one document is generated, even if the SELECT retrieves more than one record. The structure of the DTD output is described in "Document Type Definition (DTD) Specification".
This XML Create DTD method can for example be used in a corrective constraint, to fill or update a database column with the result of the DTD output.
INVOKE XML.CreateDTD WITH
SELECT expression, expression...
The possible values for expression are:
OLD( column )
Only the selected columns are generated in the DTD output.
The FROM clause may only contains a single table or logical view.