32. The integration server system of claim 31 wherein data objects can be associated with one or more other data objects in the model description and wherein the associations between data objects are stored in the database, each association being an attribute of a data object represented by a column of a table in the database schema and wherein each instance of a data object is assigned an ID number in the database table, wherein the ID number of a first instance of a database object is stored in an association column of a second instance of a data object to define an association between two data objects.
31. An integration server system that enables data modeling and storage operations of data objects, the system comprising: a processor operable to execute instructions stored in a data storage medium; a relational database operable to store data accessible to the processor that updates and retrieves data in response to SQL commands; a model generator adapted to create a database schema in response to a model description defining one or more data objects, the database schema including one or more database tables configured to store a set of data object instances in the database, wherein the model generator allows mapping of attributes that are not specifically defined in the class definition, is capable of creating a single table to encompass all classes in the hierarchy and object structures having one-to-one and one-to-many mappings; an application programming interface operable to enable a client application to create instances of a data object in the database schema and provide the client application with access to the set of data object instances as separate data objects enabling the client application to perform the data modeling and storage operations of data objects, wherein the application programming interface allows client applications written in an object oriented programming language to access the data objects in the same manner as any other object in the programming language, and wherein in response to a request for creation of one or more new data objects from a client application the application programming interface coordinates a response to the request including creating an instance of the data object in the database schema and returning a reference to the data object instance to the requesting client application thereby allowing the integration server to change database schemas without changing the model application programming interface; and one or more modules that (i) create a set of functions corresponding to attributes of data objects defined by the model description including accessor functions that enable client applications to read or set attributes of instances of the data objects; (ii) enable caching; and automatically assign attribute values to columns in the database; and wherein the integration server is capable of converting data objects between different formats specific to two or more client applications based on transformation rules stored in a table of the database and automatically handling conversion of data objects from their format as stored in the database schema into a format used by the client application; and storing variable length strings in the database schema in a manner that provides improved performance as compared to storing the variable length strings in a Character Large Object (“CLOB”) data structure.