Object-oriented database abstraction and statement generation
First Claim
1. A data model for a database having at least one table containing a plurality of fields, comprising a first class of objects which correspond to tables in the database, a second class of objects which correspond to fields in the tables, and at least one additional class of object which encapsulates said first and second classes of objects and provides a layer of abstraction between programs external to the database and the structure of the database.
12 Assignments
0 Petitions
Accused Products
Abstract
An interface provides a level of abstraction between the structure of a database system and application programs which access that system. The database system is represented by a model comprised of objects which correspond to the components of the database system. An object at a higher level encapsulates information contained in these other objects regarding the structure of the database. Whenever an application program requires access to the database, it sends a message to the higher level encapsulation object. The lower-level objects implement methods which automatically generate appropriate database commands. When the encapsulation object receives a call from an application program requesting data in the database, it instructs table objects to obtain the required data. In response, the table objects invoke field objects to identify how to represent data in each of the database fields to which they correspond. The table object concatenates the responses received from each of the field objects to construct a command that is presented to the database to retrieve the desired data.
30 Citations
13 Claims
- 1. A data model for a database having at least one table containing a plurality of fields, comprising a first class of objects which correspond to tables in the database, a second class of objects which correspond to fields in the tables, and at least one additional class of object which encapsulates said first and second classes of objects and provides a layer of abstraction between programs external to the database and the structure of the database.
- 4. A data model for a database, comprising a plurality of different classes of objects which respectively correspond to different types of components of said database, and at least one additional class of object which encapsulates the other classes of objects and provides a layer of abstraction between programs external to the database and the objects that correspond to said components, wherein at least one type of object in said model contains information which identifies a relationship between a component to which said one type of object corresponds and another component that corresponds to another object of said one type.
-
7. A method for providing an interface between a database having at least one table containing a plurality of files and programs external to the database, comprising the steps of:
-
establishing a model that comprises a first class of objects which correspond to tables in said database, a second class of objects which correspond to fields in the tables, and a third class of object which encapsulates the first and second classes of objects and provides a layer of abstraction between programs external to the database and the structure of the database;
receiving a request at said third class of object which identifies data that is to be accessed in the database; and
invoking objects in at least one of said other classes to construct a command to retrieve data from the database components to which they correspond. - View Dependent Claims (8, 9)
-
-
10. A data model for a database of the type comprising a plurality of tables each having at least one field, said data model comprising a hierarchy of object classes including the following:
-
a first level of objects that respectively correspond to the fields in said tables and provide information about the corresponding fields;
a second level of objects that are respectively associated with the tables in said database, wherein any given object in said second level is linked to objects in said first level that correspond to fields contained in the table with which said given object is associated, and constructs a command to access data in said table in accordance with the information provided by objects in said first level; and
a third level of object that encapsulates objects at said second level and functions as an interface to receive requests from applications and invoke objects at said second level to construct commands to access data pertaining to said requests. - View Dependent Claims (11, 12, 13)
-
Specification