Introduction
This document covers the setup and use of a generic jdbc server for the Model Context Protocol (MCP), referred to as an mcp-jdbc server. It has been developed to provide Large Language Models with transparent access to jdbc-accessible data sources via a Data Source Name configured for a specific jdbc Connector (or Driver).
Server Implementation
This MCP Server for jdbc is a bridge to existing JDBC connectors registered with the host operating system’s Java Runtime.
Operating Environment Setup & Prerequisites
While the examples that follow are oriented toward the Virtuoso jdbc Connector, this guide will also work with other jdbc Connectors. We strongly encourage code contributions and usage demo submissions related to other database management systems for incorporation into this project.
Installation
-
git clone <https://github.com/OpenLinkSoftware/mcp-jdbc-server.git> -
cd mcp-jdbc-server
Java Runtime Environment Requirements & Checks
MCP server requires Java 21 or above, which you verify using: java -version
Environment Variables
As good security practice, you should use the .env file situated in the same directory as the mcp-jdbc-server to set bindings for the target Large Language Model API Key (if you want to use the OpenLink AI Layer (OPAL) via jdbc) and JDBC URL components.
jdbc.url=jdbc:virtuoso://localhost:1111
jdbc.user=dba
jdbc.password=dba
jdbc.api_key=xxx
Usage
Tools Provided
After successful installation, the following tools will be available to MCP client applications.
Overview
| name | description |
|---|---|
| jdbc_get_schemas | List database schemas accessible to connected database management system (DBMS). |
| jdbc_get_tables | List tables associated with a selected database schema. |
| jdbc_describe_table | Provide the description of a table associated with a designated database schema. This includes information about column names, data types, nulls handling, autoincrement, primary key, and foreign keys |
| jdbc_filter_table_names | List tables, based on a substring pattern from the q input field, associated with a selected database schema. |
| jdbc_query_database | Execute a SQL query and return results in JSONL format. |
| jdbc_execute_query | Execute a SQL query and return results in JSONL format. |
| jdbc_execute_query_md | Execute a SQL query and return results in Markdown table format. |
| jdbc_spasql_query | Execute a SPASQL query and return results. |
| jdbc_sparql_query | Execute a SPARQL query and return results. |
| jdbc_virtuoso_support_ai | Interact with the Virtuoso Support Assistant/Agent – a Virtuoso-specific feature for interacting with LLMs |
Detailed Description
-
jdbc_get_schemas
- Retrieve and return a list of all schema names from the connected database.
- Input parameters:
user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns a JSON string array of schema names.
-
jdbc_get_tables
- Retrieve and return a list containing information about tables in a specified schema. If no schema is provided, uses the connection’s default schema.
- Input parameters:
schema(string, optional): Database schema to filter tables. Defaults to connection default.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns a JSON string containing table information (e.g., TABLE_CAT, TABLE_SCHEM, TABLE_NAME, TABLE_TYPE).
-
jdbc_filter_table_names
- Filters and returns information about tables whose names contain a specific substring.
- Input parameters:
q(string, required): The substring to search for within table names.schema(string, optional): Database schema to filter tables. Defaults to connection default.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns a JSON string containing information for matching tables.
-
jdbc_describe_table
- Retrieve and return detailed information about the columns of a specific table.
- Input parameters:
schema(string, required): The database schema name containing the table.table(string, required): The name of the table to describe.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns a JSON string describing the table’s columns (e.g., COLUMN_NAME, TYPE_NAME, COLUMN_SIZE, IS_NULLABLE).
-
jdbc_query_database
- Execute a standard SQL query and return the results in JSON format.
- Input parameters:
query(string, required): The SQL query string to execute.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns query results as a JSON string.
-
jdbc_query_database_md
- Execute a standard SQL query and return the results formatted as a Markdown table.
- Input parameters:
query(string, required): The SQL query string to execute.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns query results as a Markdown table string.
-
jdbc_query_database_jsonl
- Execute a standard SQL query and return the results in JSON Lines (JSONL) format (one JSON object per line).
- Input parameters:
query(string, required): The SQL query string to execute.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns query results as a JSONL string.
-
jdbc_spasql_query
- Execute a SPASQL (SQL/SPARQL hybrid) query return results. This is a Virtuoso-specific feature.
- Input parameters:
query(string, required): The SPASQL query string.max_rows(number, optional): Maximum number of rows to return. Defaults to 20.timeout(number, optional): Query timeout in milliseconds. Defaults to 30000.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns the result from the underlying stored procedure call (e.g.,
Demo.demo.execute_spasql_query).
-
jdbc_sparql_query
- Execute a SPARQL query and return results. This is a Virtuoso-specific feature.
- Input parameters:
query(string, required): The SPARQL query string.format(string, optional): Desired result format. Defaults to ‘json’.timeout(number, optional): Query timeout in milliseconds. Defaults to 30000.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns the result from the underlying function call (e.g.,
"UB".dba."sparqlQuery").
-
jdbc_virtuoso_support_ai
- Utilizes a Virtuoso-specific AI Assistant function, passing a prompt and optional API key. This is a Virtuoso-specific feature.
- Input parameters:
prompt(string, required): The prompt text for the AI function.api_key(string, optional): API key for the AI service. Defaults to “none”.user(string, optional): Database username. Defaults to “demo”.password(string, optional): Database password. Defaults to “demo”.url(string, optional): JDBC URL connection string.
- Returns the result from the AI Support Assistant function call (e.g.,
DEMO.DBA.OAI_VIRTUOSO_SUPPORT_AI).
Claude Desktop
Add the following to claude_desktop_config.json:
{
"mcpServers": {
"jdbc": {
"command": "java",
"args": ["-jar", "/path/to/mcp-jdbc-server/MCPServer-1.0.0-runner.jar"],
"env": {
"jdbc.url": "jdbc:virtuoso://localhost:1111",
"jdbc.user": "username",
"jdbc.password": "password",
"jdbc.api_key": "sk-xxx"
}
}
}
}
Troubleshooting
For easy troubleshooting perform the following steps:
-
Install the MCP Inspector:
npm install -g @modelcontextprotocol/inspector -
Start the inspector:
npx @modelcontextprotocol/inspector java -jar /path/to/mcp-jdbc-server/MCPServer-1.0.0-runner.jar
Access the provided URL to troubleshoot server interactions.