Since abstract data types (also called user-defined data types) are supported only for ORDBMSs, the corresponding values make sense only when connected to databases that have this capability. Two such RDBMSs are currently supported: Oracle® and Informix® Universal Server, also called Informix9 in the Rogue Wave DB Link documentation.

The following items are described:

A descriptor is used to describe abstract data types. This descriptor is implemented by the class IldADTDescriptor.

Such a descriptor can be embedded in an IldDescriptor instance if the described column or parameter is of a user-defined type, that is, when the function IldDescriptor::getType returns either IldObjectType or IldCollectionType objects.

A value of a user-defined data type is always an instance of IldADTValue, whether a “horizontal” structure (object for Oracle, named row or unnamed row for Informix Universal Server) or a “vertical” structure (varray or nested table for Oracle, list, set, or multiset for Informix US).

To differentiate between them, the user-defined data type descriptor can be queried using the function getType, which returns an IldADTType value, according to Table 4.4:

The type of a user-defined data type descriptor can only be a value from the enumeration IldADTType declared in the file ild.h. In other words, an IldADTDescriptor instance can represent one of the following:

Values of an abstract data type are handled using instances of the class IldADTValue. Such a value keeps a reference to the abstract data type descriptor, which can be accessed by calling the function IldADTValue::getDescriptor.

An IldADTValue object is returned by the function IldRequest::getColADTValue. This object becomes the application’s property. This means that the application must delete it once done with it.

Once a parameter has been bound to the Rogue Wave DB Link types IldObjectType or IldCollectionType using the member function IldRequest::bindParam, values can be passed using the overloaded function setParamValue. The first parameter of this function can be deleted immediately after the call because Rogue Wave DB Link copies it.

Whether the object represents the value of an object type or the value of a collection type, the individual attribute or slot values are retrieved using the same accessor functions of the form get<type>Value() where <type> can be one of: