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Copyright (c) 2025 Software Tree

Gilhari Relationships With Implicit Attributes Example

Demonstrates implicit attributes for automatic foreign key management in contained objects

Gilhari is a Docker-compatible microservice framework that provides RESTful Object-Relational Mapping (ORM) functionality for JSON objects with any relational database.

Remarkably, Gilhari automates REST APIs (POST, GET, PUT, DELETE, etc.) handling, JSON CRUD operations, and database schema setup — no manual coding required.

About This Example

This repository contains an example showing how to use Gilhari's implicit attributes feature, where attributes of a contained (referenced) object are automatically initialized by the ORM using foreign key values derived from the containing (referencing) object, simplifying JSON object creation.

The example uses the base Gilhari docker image (softwaretree/gilhari) to easily create a new docker image (gilhari_relationships_implicit_attribs_example) that can run as a RESTful microservice (server) to persist app specific JSON objects with relational mappings.

This example can be used standalone as a RESTful microservice or optionally with the ORMCP Server.

Related:

• ORMCP Documentation: https://github.com/softwaretree/ormcp-docs
• ORMCP/Gilhari Examples: https://github.com/softwaretree/ormcp-docs#examples - Comprehensive list of examples

Note: This example is also included in the Gilhari SDK distribution. If you have the SDK installed, you can use it directly from the examples/gilhari_relationships_implicit_attribs_example directory without cloning.

Example Overview

The example showcases a JSON object model with two types of objects: A and B

Object Model Overview:

• A: Parent object that contains a B object
• B: Child object contained by A with an implicit aId attribute
• Attributes:
  • A: aId (int), aString (string), aBoolean (boolean), aFloat (double), aDate (long/milliseconds), aB (B object)
  • B: bId (int), bInt (int), bString (string), aId (int - IMPLICIT, auto-populated)
• Database Tables: A, B (stored in separate tables)

What Makes This Example Different?

This example demonstrates the implicit attributes feature:

Implicit Attributes Feature:

• The aId attribute in the B object is marked as IMPLICIT_ATTRIB in the ORM specification
• When creating an A object with a contained B object, you do not need to specify the aId value in the B object
• The ORM automatically populates the B object's aId with the value from the parent A object's aId
• This simplifies JSON object creation and reduces redundancy in client code

Key Benefits:

• Cleaner JSON: No need to repeat foreign key values in child objects
• Automatic management: ORM handles the foreign key relationships
• Reduced errors: Eliminates potential mismatches between parent and child IDs
• BYVALUE semantics: Contained B objects are deleted when their parent A object is deleted

Configuration: See config/gilhari_relationships_implicit_attribs_example.jdx for how to configure implicit attributes using IMPLICIT_ATTRIB directive.

A Object Structure (with contained B object - without explicit aId in B)

{
  "aId": 1,
  "aString": "aString_1",
  "aBoolean": true,
  "aFloat": 1.1,
  "aDate": 347184000001,
  "aB": {
    "bId": 100,
    "bInt": 100,
    "bString": "bString_1"
  }
}

Note: The aId is not specified in the B object. The ORM will automatically populate it from the parent A object's aId value.

A Object After Retrieval (B object now includes aId)

{
  "aId": 1,
  "aString": "aString_1",
  "aBoolean": true,
  "aFloat": 1.1,
  "aDate": 347184000001,
  "aB": {
    "bId": 100,
    "aId": 1,
    "bInt": 100,
    "bString": "bString_1"
  }
}

Note: When retrieved, the B object includes the aId value that was automatically populated by the ORM.

Project Structure

gilhari_relationships_implicit_attribs_example/
├── src/                           # Container domain model classes
│   └── com/softwaretree/...      # A.java, B.java
├── config/                        # Configuration files
│   ├── gilhari_relationships_implicit_attribs_example.jdx  # ORM specification with IMPLICIT_ATTRIB
│   └── classnames_map_example.js
├── bin/                           # Compiled .class files
├── Dockerfile                     # Docker image definition
├── gilhari_service.config         # Service configuration
├── compile.cmd / .sh              # Compilation scripts
├── build.cmd / .sh                # Docker build scripts
├── run_docker_app.cmd / .sh       # Docker run scripts
├── curlCommands.cmd / .sh         # API testing scripts
└── curlCommandsPopulate.cmd / .sh # Sample data population scripts

Source Code

The src directory contains the declarations of the underlying shell (container) classes (e.g., A, B) that are used to define the object-relational mapping (ORM) specification for the corresponding conceptual domain-specific JSON object model classes:

• A and B classes: Simple shell (container) classes (.java files) corresponding to the domain-specific JSON object model classes of related entities (Container domain model classes)
• JDX_JSONObject: Base class of the container domain model classes for handling persistence of domain-specific JSON objects
• Container domain model classes: Only need to define two constructors, with most processing handled by the JDX_JSONObject superclass

Note: Gilhari does not require any explicit programmatic definitions (e.g., ES6 style JavaScript classes) for domain-specific JSON object model classes. It handles the data of domain-specific JSON objects using instances of the container domain model classes and the ORM specification.

Configurations

A declarative ORM specification for the domain-specific JSON object model classes and their attributes is defined in config/gilhari_relationships_implicit_attribs_example.jdx using the container domain model classes. This file defines the mappings between JSON objects and database tables, including the IMPLICIT_ATTRIB configuration.

Key points:

• Update the database URL and JDBC driver in this file according to your setup
• See JDX_DATABASE_JDBC_DRIVER_Specification_Guide (.md or .html) for guides on configuring different databases
• The container domain model classes (like A, B) corresponding to the conceptual domain-specific JSON object model classes are defined as subclasses of the JDX_JSONObject class
• Appropriate mappings for the domain-specific JSON object model classes are defined in the ORM specification file using the corresponding container domain model classes
• IMPLICIT_ATTRIB configuration enables automatic foreign key population from parent objects

For comprehensive details on defining and using container classes and the ORM specification for JSON object models, refer to the "Persisting JSON Objects" section in the JDX User Manual.

Implicit Attribute Configuration

The key to this example is in the ORM specification file (config/gilhari_relationships_implicit_attribs_example.jdx), where the aId attribute in the B class is marked as implicit.

Parent Class (A) with BYVALUE Relationship:

CLASS .A TABLE A
    VIRTUAL_ATTRIB aId ATTRIB_TYPE int
    VIRTUAL_ATTRIB aString ATTRIB_TYPE java.lang.String
    VIRTUAL_ATTRIB aBoolean ATTRIB_TYPE boolean
    VIRTUAL_ATTRIB aFloat ATTRIB_TYPE double
    VIRTUAL_ATTRIB aDate ATTRIB_TYPE long
    
    PRIMARY_KEY aId 
    SQLMAP FOR aDate SQLTYPE DATE
    RELATIONSHIP aB REFERENCES .B BYVALUE REFERENCED_KEY AKEY WITH aId
;

Child Class (B) with IMPLICIT_ATTRIB:

CLASS .B TABLE B
    VIRTUAL_ATTRIB bId ATTRIB_TYPE int
    VIRTUAL_ATTRIB bInt ATTRIB_TYPE int
    VIRTUAL_ATTRIB bString ATTRIB_TYPE java.lang.String
    IMPLICIT_ATTRIB aId ATTRIB_TYPE int  // <-- Implicit attribute
    
    PRIMARY_KEY bId 
    REFERENCE_KEY AKEY aId
;

How it works:

1. When creating an A object, you include a B object in the aB attribute
2. You omit the aId field in the B object JSON
3. The ORM automatically populates B's aId with the value from A's aId
4. The REFERENCE_KEY directive links the implicit attribute to the parent relationship
5. When queried, the B object includes the aId value

Docker Configuration

The Dockerfile builds a RESTful Gilhari microservice using:

• Base Gilhari image (softwaretree/gilhari)
• Compiled domain model (.class) files
• Configuration files including the ORM specification and a JDBC driver

Service Configuration

The gilhari_service.config file specifies runtime parameters for the RESTful Gilhari microservice:

{
  "gilhari_microservice_name": "gilhari_relationships_implicit_attribs_example",
  "jdx_orm_spec_file": "./config/gilhari_relationships_implicit_attribs_example.jdx",
  "jdbc_driver_path": "/node/node_modules/jdxnode/external_libs/sqlite-jdbc-3.50.3.0.jar",
  "jdx_debug_level": 5,
  "jdx_force_create_schema": "true",
  "jdx_persistent_classes_location": "./bin",
  "classnames_map_file": "config/classnames_map_example.js",
  "gilhari_rest_server_port": 8081
}

Service Configuration Parameters

Parameter	Description	Default
gilhari_microservice_name	Optional name to identify this Gilhari microservice. The name is logged on console during start up	-
jdx_orm_spec_file	Location of the ORM specification file containing mapping for persistent classes	-
jdbc_driver_path	Path to the JDBC driver (.jar) file. SQLite driver included by default	-
jdx_debug_level	Debug output level (0-5). 0 = most verbose, 5 = minimal. Level 3 outputs all SQL statements	5
jdx_force_create_schema	Whether to recreate database schema on each run. true = useful for development, false = create only once	false
jdx_persistent_classes_location	Root location for compiled persistent (Container domain model) classes. Can be a directory (e.g., ./bin) or a JAR file path. Used as a Java CLASSPATH	-
classnames_map_file	Optional JSON file that can map names of container domain model classes to (simpler) object class (type) names (e.g., by omitting a package name) to simplify REST URL	-
gilhari_rest_server_port	Port number for the RESTful service. This port number may be mapped to different port number (e.g., 80) by a docker run command.	8081

Build Files

• compile.cmd / compile.sh: Compiles the container domain model classes
• sources.txt: Lists the names of the container domain model class source (.java) files for compilation
• build.cmd / build.sh: Creates the Gilhari Docker image (gilhari_relationships_implicit_attribs_example) using the local Dockerfile

Note: Compilation targets JDK version 1.8, which is compatible with the current Gilhari version.

Quick Start

For Quick Evaluation (No SDK Required)

If you just want to see this example in action without modifications:

1. Clone this repository (pre-compiled classes included)
2. Install Docker
3. Build and run (skip compilation step)

For Development and Customization

If you want to modify the object model or create your own Gilhari microservices:

1. Gilhari SDK: Download and install from https://softwaretree.com
2. JX_HOME environment variable: Set to the root directory of your Gilhari SDK installation
3. Java Development Kit (JDK 1.8+) for compilation
4. Docker installed on your system

Note: The Gilhari SDK contains necessary libraries (JARs) and base classes required for compiling container domain model classes. While pre-compiled .class files are included in this repository for immediate use, you'll need the SDK to make any modifications to the object model or to create your own Gilhari microservices.

Build and Run

Option 1: Quick Run (Using Pre-compiled Classes)

Skip compilation and go straight to Docker:

# Windows
build.cmd
run_docker_app.cmd

# Linux/Mac
./build.sh
./run_docker_app.sh

Option 2: Compile and Run (For Modifications)

If you've made changes to the source code:

1. Ensure JX_HOME is set to your Gilhari SDK installation directory

2. Compile the classes:

   # Windows
   compile.cmd
   
   # Linux/Mac
   ./compile.sh

3. Build and run the Docker container:

   # Windows
   build.cmd
   run_docker_app.cmd
   
   # Linux/Mac
   ./build.sh
   ./run_docker_app.sh

REST API Usage

Once running, access the Gilhari microservice at:

http://localhost:<port>/gilhari/v1/:className

Example endpoints:

http://localhost:80/gilhari/v1/A
http://localhost:80/gilhari/v1/B

Supported HTTP Methods

Method	Purpose	Example
GET	Retrieve objects	GET /gilhari/v1/A
POST	Create objects	POST /gilhari/v1/A
PUT	Update objects	PUT /gilhari/v1/A
PATCH	Partial update	PATCH /gilhari/v1/A
DELETE	Delete objects	DELETE /gilhari/v1/A

Example Operations

Create A object with contained B object (without aId in B):

curl -X POST http://localhost:80/gilhari/v1/A \
  -H "Content-Type: application/json" \
  -d '{
    "entity": {
      "aId": 1,
      "aString": "aString_1",
      "aBoolean": true,
      "aFloat": 1.1,
      "aDate": 347184000001,
      "aB": {
        "bId": 100,
        "bInt": 100,
        "bString": "bString_1"
      }
    }
  }'

Note: The aId is not specified in the B object. It will be automatically populated from the parent A's aId.

Query all A objects (deep - includes B with aId populated):

curl -X GET "http://localhost:80/gilhari/v1/A" \
  -H "Content-Type: application/json"

Shallow query (exclude B objects):

curl -X GET "http://localhost:80/gilhari/v1/A?deep=false" \
  -H "Content-Type: application/json"

Query with path expression:

curl -X GET "http://localhost:80/gilhari/v1/A?filter=jdxObject.aB.bInt>100" \
  -H "Content-Type: application/json"

Query all B objects (will show auto-populated aId):

curl -X GET "http://localhost:80/gilhari/v1/B" \
  -H "Content-Type: application/json"

Delete A object (cascades to B):

curl -X DELETE "http://localhost:80/gilhari/v1/A?filter=aId=1"

Testing the API

Comprehensive test scripts:

1. curlCommands.cmd / .sh - Demonstrates implicit attribute behavior

   Demonstrates:

   • Creating A objects without specifying aId in B objects
   • Verifying aId is auto-populated in retrieved B objects
   • Deep and shallow queries
   • Path expressions for filtering
   • Cascading deletes

2. curlCommandsPopulate.cmd / .sh - Population with data

   Demonstrates:

   • Sample data population
   • Multiple object creation scenarios
   • A objects with and without B objects
   • Querying to verify implicit attribute population

Run the scripts to generate a curl.log file with all responses:

# Windows
curlCommands.cmd
curlCommandsPopulate.cmd

# Linux/Mac
chmod +x curlCommands.sh curlCommandsPopulate.sh
./curlCommands.sh
./curlCommandsPopulate.sh

# Custom port
curlCommands.cmd 8899
curlCommandsPopulate.sh 8899

The scripts demonstrate the implicit attributes feature where the B object's aId is automatically populated from the parent A object, simplifying JSON object creation.

Other options:

• Postman: Import the endpoints for interactive testing
• Browser: Access GET endpoints directly
• Any REST Client: Standard HTTP methods work with any REST client
• ORMCP Server (optional): Use ORMCP Server tools for AI-powered interactions

Using with ORMCP Server (Optional)

This Gilhari microservice can be used with the ORMCP Server for AI-powered database interactions:

1. Start this Gilhari microservice (as shown in Quick Start)
2. Configure ORMCP Server to connect to this microservice endpoint
3. Use ORMCP tools to query and manipulate A and B objects through natural language

The ORMCP Server will automatically handle the implicit attribute behavior when creating objects.

For more information on ORMCP Server:

• ORMCP Documentation: https://github.com/softwaretree/ormcp-docs
• ORMCP/Gilhari Examples: https://github.com/softwaretree/ormcp-docs#examples
• Product Website: https://www.softwaretree.com/products/ormcp/

Development Tools

Docker Container Access

Shell into a running container:

# Find container ID
docker ps

# Access container
docker exec -it <container-id> bash

View Logs

docker logs <container-id>

Stop Container

docker stop <container-id>

Additional Resources

• JDX User Manual: "Persisting JSON Objects" section for detailed ORM specification documentation
• Gilhari SDK Documentation: The SDK available for download at https://softwaretree.com
• ORMCP Documentation: https://github.com/softwaretree/ormcp-docs
• Database Configuration Guide: See JDX_DATABASE_JDBC_DRIVER_Specification_Guide.md
• operationDetails Documentation: See operationDetails_doc.md for GraphQL-like query capabilities

Platform Notes

Script files are provided for both Windows (.cmd) and Linux/Mac (.sh).

Linux/Mac users: Make scripts executable before running:

chmod +x *.sh

Troubleshooting

Common Issues

Problem: Docker image build fails

• Solution: Ensure the base Gilhari image is pulled: docker pull softwaretree/gilhari

Problem: Compilation errors

• Solution: Verify JDK 1.8+ is installed and JX_HOME environment variable is set correctly

Problem: Port 80 already in use

• Solution: Modify run_docker_app script to use a different port (e.g., -p 8080:8081)

Problem: Database connection errors

• Solution: Check config/gilhari_relationships_implicit_attribs_example.jdx for correct database URL and JDBC driver path

Problem: The implicit aId is not being populated in B objects

• Solution: Verify the ORM specification has IMPLICIT_ATTRIB aId in the B class and REFERENCED_KEY AKEY in the A class's RELATIONSHIP declaration

Problem: Error when including aId in B object during creation

• Solution: When aId is IMPLICIT_ATTRIB, you should omit it in the JSON. If you include it, the value may be ignored or cause errors

Support

For issues or questions:

• ORMCP Documentation & Issues: https://github.com/softwaretree/ormcp-docs/issues
• This example: https://github.com/SoftwareTree/gilhari_relationships_implicit_attribs_example/issues
• Gilhari SDK: Contact support at gilhari_support@softwaretree.com

License

This example code is licensed under the MIT License - see the LICENSE file for details.

Important: This license applies ONLY to the example code in this repository. The Gilhari software (including the softwaretree/gilhari Docker image and Gilhari SDK) and the embedded JDX ORM software are proprietary products owned by Software Tree.

The Gilhari Docker image includes an evaluation license for testing purposes. For production use or licensing beyond the evaluation period, please visit https://www.softwaretree.com or contact gilhari_support@softwaretree.com.

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Ready to try it? Start with the Quick Start section above!