Summary of DBMS_TRANSFORM Subprograms

Table 76-1 DBMS_TRANSFORM Subprograms

Subprograms	Description
CREATE_TRANSFORMATION Procedure	Creates a transformation that maps an object of the source type to an object of the destination type
MODIFY_TRANSFORMATION Procedure	Modifies an existing transformation
DROP_TRANSFORMATION Procedure	Drops the given transformation

CREATE_TRANSFORMATION Procedure

This procedure creates a transformation that maps an object of the source type to an object of the target type. The transformation expression can be a SQL expression or a PL/SQL function. It must return an object of the target type.

Syntax

DBMS_TRANSFORM.CREATE_TRANSFORMATION (
    schema               VARCHAR2(30),
    name                 VARCHAR2(30),
    from_schema          VARCHAR2(30),
    from_type            VARCHAR2(30),
    to_schema            VARCHAR2(30),
    to_type              VARCHAR2(30),
    transformation       VARCHAR2(4000)); 

Parameters

Table 76-2 CREATE_TRANSFORMATION Procedure Parameters

Parameter	Description
schema	Specifies the schema of the transformation
name	Specifies the name of the transformation
from_schema	Specifies the schema of the source type
from_type	Specifies the source type
to_schema	Specifies the target type schema
to_type	Specifies the target type
transformation	Specifies the transformation expression, returning an object of the target type. If the target type is an ADT, the expression must be a function returning an object of the target type or a constructor expression for the target type. You can choose not to specify a transformation expression and instead specify transformations for attributes of the target type using MODIFY_TRANSFORMATION.

MODIFY_TRANSFORMATION Procedure

This procedure modifies (or creates) the mapping for the specified attribute of the target type. The transformation expression must be a SQL expression or a PL/SQL function returning the type of the specified attribute of the target type. An attribute number zero must be specified for a scalar target type. If the target type is an ADT, and the attribute_number is zero, then the expression must be a PL/SQL function returning an object of the target type or a constructor expression for the target type.

Syntax

DBMS_TRANSFORM.MODIFY_TRANSFORMATION (
    schema            VARCHAR2(30)
    name              VARCHAR2(30),
    attribute_number  INTEGER,
    transformation    VARCHAR2(4000));

Parameters

Table 76-3 MODIFY_TRANSFORMATION Procedure Parameters

Parameter	Description
schema	Specifies the schema of the transformation
name	Specifies the name of the transformation
attribute_number	Must be zero for a scalar target type
transformation	The transformation expression must be a SQL expression or a PL/SQL function returning the type of the specified attribute of the target type

DROP_TRANSFORMATION Procedure

This procedure drops the given transformation.

Syntax

DBMS_TRANSFORM.DROP_TRANSFORMATION (
    schema      VARCHAR2(30),
    name        VARCHAR2(30));

Parameters

Table 76-4 DROP_TRANSFORMATION Procedure Parameters

Parameter	Description
schema	Specifies the schema of the transformation
name	Specifies the name of the transformation