JVLink MCP Server

Instructions

Implementation Reference

• src/jvlink_mcp_server/server.py:634-655 (handler)

  The execute_template_query tool handler function, which renders a SQL template and executes the resulting query against the database.

  @mcp.tool()
  def execute_template_query(template_name: str, **params) -> dict:
      """テンプレートからSQLを生成して実行"""
      try:
          sql, query_params = render_template(template_name, **params)
          with DatabaseConnection() as db:
              result_df = db.execute_safe_query(sql, params=query_params)
              return {
                  "success": True,
                  "template": template_name,
                  "parameters": params,
                  "generated_sql": sql,
                  "query_params": list(query_params),
                  "rows": len(result_df),
                  "columns": result_df.columns.tolist(),
                  "data": result_df.head(100).to_dict(orient="records"),
                  "note": "max 100 rows" if len(result_df) > 100 else None
              }
      except ValueError as e:
          return {"success": False, "error": str(e), "hint": "Use list_query_templates to see available templates"}
      except Exception as e:
          return {"success": False, "error": str(e)}