JDBC Developer's Guide - Supra - Cincom

In the previous example, the application had to perform the following steps inorder to use custom mapping to insert and/or update a database instance:1. Acquire a custom mapped instance (either existing object for update, orusing the constructor that takes the Connection as a parameter for insert).2. Modify the attributes of the custom mapped class.3. Invoke the writeSQL method passing the custom mapped instance as anargument. (This is possible since the custom mapped instance is a subclassof ordbObject, and ordbObject implements the SQLInput and SQLOuputinterfaces.)Writing your own custom mapping classesAlthough the ddltojava utility is the easiest way to generate java classes foruse with custom mapping, you can write your own custom java classes.Custom java classes used for mapping to Cincom ORDB classes must:♦♦Implement the SQLData interfaceExtend the ordbjava.jdbc.ordbObject classUnderstanding the SQLData interfaceThe SQLData interface defines methods that translate between SQL and Javafor Cincom ORDB database objects.If you create a custom Java class that implements SQLData, you must provide areadSQL() method and writeSQL() method as defined by the SQLData interface.The JDBC driver calls your readSQL() method to read a stream of data valuesfrom the database and populate an instance of your custom Java class.Typically, the driver would use this method as part of an ResultSet.getObject()call.The Cincom ORDB JDBC Driver never invokes the writeSQL() method,but application developers can invoke the writeSQL() method to insertand/or update instances in the database.Understanding the SQLInput and SQLOutput interfaces. The class,ordbObject class of the Cincom ORDB JDBC driver, implements the SQLInputand SQLOutput interfaces. It is not necessary to implement the SQLOutput orSQLInput objects. The JDBC drivers will do this for you.JDBC Developer's Guide, P25-9504-03 Page 58Chapter: 4. Cincom ORDB ExtensionsSection: Creating custom Java classes for Cincom ORDB objects