is used for the custom mapping of SQL user-defined types.
This interface must be implemented by a service that is
registered in a type mapping. It is expected that this interface
will normally be implemented by a tool. The methods in this interface
are called by the driver and are never called by a programmer
directly.
populates this object with data read from the database.
The implementation of the method must follow this protocol:
It must read each of the attributes or elements of the SQL
type from the given input stream. This is done
by calling a method of the input stream to read each
item, in the order that they appear in the SQL definition
of the type. The method
readSQL
then assigns the data to appropriate fields or elements (of this
or other objects).
Specifically, it must call the appropriate
XSQLInput.readXXX
method(s) to do the following:
for a Distinct Type, read its single data element;
for a Structured Type, read a value for each attribute of the SQL type.
The SDBC driver initializes the input stream with a type map
before calling this method, which is used by the appropriate
SQLInput.readXXX
method on the stream.
The implementation of the method must follow this protocol:
It must write each of the attributes of the SQL type to the given output
stream. This is done by calling a method of the output stream to write
each item, in the order that they appear in the SQL definition of the type.
Specifically, it must call the appropriate
XSQLOutput.writeXXX
method(s) to do the following:
for a Distinct Type, write its single data element;
for a Structured Type, write a value for each attribute of the SQL type.
