|Oracle9i Supplied PL/SQL Packages and Types Reference
Release 1 (9.0.1)
Part Number A89852-02
DBMS_METADATA , 7 of 11
ADD_TRANSFORM specifies a transform that
FETCH_xxx applies to the XML representation of the retrieved objects. It is possible to add more than one transform.
add_transform(handle IN NUMBER, name IN VARCHAR2, encoding IN VARCHAR2 DEFAULT NULL) RETURN NUMBER;
The handle returned from
The name of the transform. If the name is
The name of NLS character set (see National Language Support Guide) in which the stylesheet pointed to by name is encoded. This is only valid if name is a URL. If left NULL and the URL is external to the database (e.g, /usr/williams/xsl/mystylesheet.xsl), UTF-8 encoding is assumed. If left NULL and the URL is internal to the database, that is, it begins with /oradb/ (see [XPATH-SUPP]), then the database character set is assumed to be the encoding.
An opaque handle to the transform. This handle is used as input to
SET_TRANSFORM_PARAM. Note that this handle is different from the handle returned by
OPEN; it refers to the transform, not the set of objects to be retrieved.
NULLor invalid value was supplied for an input parameter. The error message text identifies the parameter.
ADD_TRANSFORMwas called after the first call to
OPENcontext. After the first call to
FETCH_xxxis made, no further calls to
ADD_TRANSFORMfor the current
OPENcontext are permitted.
With no transforms added, objects are returned by default as XML documents. You call
ADD_TRANSFORM to specify an XSL-T stylesheet to transform the returned documents.
You can call
ADD_TRANSFORM more than once to apply multiple transforms to the returned XML documents.
FETCH_xxx will apply the transforms in the order in which they were specified, the output of the first transform being used as input to the second, and so on.
The encoding parameter must be specified if either of the following is true:
An example of the latter might be if the database-internal URL pointed to an NCLOB or NVARCHAR column. Normally, this need not be specified, although explicitly setting it to US7ASCII (if applicable) results in slightly better XML parsing performance.