System and method of translating a relational database into an XML document and vice versa

• US 8,321,478 B2
• Filed: 09/02/2008
• Issued: 11/27/2012
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Joseph S.P. Fong
• Original Assignee: Joseph S.P. Fong
• Inventors: Fong, Joseph S. P.
• Primary Examiner(s): Cao, Phuong Thao
• Application Number:
  US12/202,714
• Publication Number:
  US 20080320023A1
• Time in Patent Office: 1,547 Days
• Field of Search: 707/999.101, 707/809, 707/E17.124, 707/756, 707/E17.048
• US Class Current: 707/809
• CPC Class Codes: G06F 40/151 Transformation

Abstract

A method of translating a relational database into an XML document comprises generating an Extended Entity Relationship model from relational schema associated with the relational database and applying a schema translation process to the Extended Entity Relationship model to map the relational schema into a Document Type Definition (DTD) of an XML schema. An XML Tree Model is then generated from the Document Type Definition, the XML Tree Model being representative of one or more data semantics of the relational schema which are preserved as one or more data semantics in the XML document. Relational data from the relational database is then converted into the XML document using the relational schema and the XML schema from the Document Type Definition and/or the XML Tree Model. There is also described a method of translating an XML database into a relational database which comprises the reversal of the steps of the disclosed method, and a system for implementing both methods.

Claims

1. A method of translating a relational database into an XML document comprising the steps of:

generating, using a computer, an Extended Entity Relationship (EER) model from a relational schema associated with said relational database;

applying, using the computer, a schema translation process to the Extended Entity Relationship model to map the relational schema into a Document Type Definition (DTD) of an XML schema;

generating, using the computer, a XML Tree Model from said Document Type Definition representative of one or more data semantics of the relational schema which are preserved as one or more data semantics in said XML document; and

converting, using the computer, relational data from said relational database into said XML document by;

using said relational schema and said XML schema from one selected from a group consisting of;

said Document Type Definition, said XML Tree Model and a combination thereof, wherein structural constraints of any relationships from said relational database are preserved using identifiers (ID), identifier reference (IDREF) and instance occurrence indicators;

converting, using the computer, one or more relations associated with relational data in said relational database into a Java Document Object Model (DOM); and

manipulating, using the computer, said XML document using said Java Document Object Model.

2. The method according to claim 1, wherein the step of generating said Extended Entity Relationship model comprises reverse-engineering logical relational schema associated with said relational database.

3. The method according to claim 1, wherein the step of applying a schema translation process comprises mapping the relational schema with associated relational schema constraints into said Document Type Definition.

4. The method according to claim 1, wherein the step of applying a schema translation process comprises mapping the relational schema into a topological XML Document Type Definition.

5. The method according to claim 1, wherein the step of applying a schema translation process comprises defining a root element prior to mapping the relational schema into said Document Type Definition (DTD), said root element being representative of an element in said relational database.

6. The method according to claim 5, wherein the step of defining said root element comprises selecting said root element.

7. The method according to claim 5, wherein the step of defining said root element comprises selecting said root element from a relational entity table in said relational database.

8. The method according to claim 5, wherein said relational database comprises one or more entities, and said XML document comprises said root element, and one or more sub-elements, and wherein the step of applying a schema translation process further comprises one or more of the following steps after defining said root element:

(a) mapping a weak entity from said relational database into said XML document;

(b) mapping participation between entities in said relational database into said XML document;

(c) mapping cardinality between entities in said relational database into said XML document;

(d) mapping aggregation between entities in said relational database into said XML document;

(e) mapping one or more ISA relationships between entities in said relational database into said XML document;

(f) mapping one or more generalisations between entities in said relational database into said XML document;

(g) mapping one or more categorisations between entities in said relational database into said XML document; and

(h) mapping one selected from a group consisting of;

one or more single, multiple (n-ary) relationships and a combination thereof between entities in said relational database into said XML document.

9. The method according to claim 1, wherein said relational database comprises one or more entities, and said XML document comprises a root element, and one or more sub-elements, and wherein the step of applying a schema translation process comprises mapping related entities in said relational database into relevant elements in said XML document based on navigability of the entities.

10. The method according to claim 8, wherein each mapping step generates a new XML document, and wherein the step of converting relational data from said relational database into said XML document comprises:

(a) converting one or more relations associated with relational data in said relational database into a Document Object Model (DOM); and

(b) integrating XML documents using said Document Object Model to form an XML database corresponding to said relational database.

11. The method according to claim 1 wherein the step of generating an XML Tree Model comprises generating a plurality of XML Tree Models representative of one or more data semantics of the relational schema.

12. The method according to claim 10, further comprising updating said relational database and said XML database by translating an update transaction from said relational database in Structural Query Language into an update transaction of said XML database as a Document Object Model.

13. The method according to claim 12, wherein said transactions update said relational database and said XML database concurrently to produce a synchronized update.

14. The method according to claim 12, wherein said updating of said relational database is effected prior to or after said update of said XML database to produce an asynchronized update.

15. The method according to claim 1, wherein the step of generating an Extended Entity Relationship (EER) model comprises recovering one or more data semantics associated with said relational schema from a classification table.

16. A method of data transmission of relational data through an XML document between a sender and a receiver over a network comprising:

translating, using a computer, a relational database into an XML document, wherein the translating comprises;

generating, using the computer, an Extended Entity Relationship (EER) model from a relational schema associated with said relational database;

applying, using the computer, a schema translation process to the Extended Entity Relationship model to map the relational schema into a Document Type Definition (DTD) of an XML schema;

generating, using the computer, a XML Tree Model from said Document Type Definition representative of one or more data semantics of the relational schema which are preserved as one or more data semantics in said XML document; and

converting, using the computer, relational data from said relational database into said XML document by;

using said relational schema and said XML schema from one selected from a group consisting of said Document Type Definition, said XML Tree Model and a combination thereof, wherein structural constraints of any relationships from said relational database are preserved using identifiers (ID), identifier reference (IDREF) and instance occurrence indicators;

converting, using the computer, one or more relations associated with relational data in said relational database into a Java Document Object Model (DOM);

manipulating, using the computer, said XML document using said Java Document Object Model;

transmitting, using the computer, from said sender said XML document over said network;

receiving at said receiver said XML document; and

converting said XML document into a local relational schema language used in said receiver.

17. The method according to claim 16, wherein the step of converting said XML document into the local relational schema used in said receiver comprises:

generating an XML Tree Model from said XML document;

generating a Document Type Definition representative of one or more data semantics of an XML schema associated with said XML document;

generating an Extended Entity Relationship (EER) model from said XML schema;

applying a schema translation process to the Extended Entity Relationship model to map the XML schema into said local relational schema representative of a relational database of said receiver, said data semantics of said XML schema being preserved as one or more data semantics in said relational database of said receiver; and

converting XML data from said XML database into said local relational database using said local relational schema and said XML schema from one selected from a group consisting of;

said Document Type Definition, said XML Tree Model and a combination thereof.

18. The method according to claim 17, wherein said network is the Internet.

19. A computer program product, stored on a non-transitory computer readable medium, for translating a relational database into an XML document during execution by a computer, the program product comprising

program code for generating an Extended Entity Relationship (EER) model from a relational schema associated with said relational database;

program code for applying a schema translation process to the Extended Entity Relationship model to map the relational schema into a Document Type Definition (DTD) of an XML schema;

program code for generating a XML Tree Model from said Document Type Definition representative of one or more data semantics of the relational schema which are preserved as one or more data semantics in said XML document;

program code for converting relational data from said relational database into said XML document by;

using said relational schema and said XML schema from one selected from a group consisting of;

said Document Type Definition, said XML Tree Model and a combination thereof, wherein structural constraints of any relationships from said relational database are preserved using identifiers (ID), identifier reference (IDREF) and instance occurrence indicators;

converting one or more relations associated with relational data in said relational database into a Java Document Object Model (DOM); and

manipulating said XML document using said Java Document Object Model.