base_columnDescription
Retrieve detailed column information for Teradata database tables, including data types and constraints, with SQL query metadata returned.
Instructions
Shows detailed column information about a database table via SQLAlchemy, bind parameters if provided (prepared SQL), and return the fully rendered SQL (with literals) in metadata.
Arguments: database_name - Database name obj_name - table or view name
Returns: ResponseType: formatted response with query results + metadata
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| database_name | Yes | ||
| obj_name | Yes |
Implementation Reference
- The handler function that implements the core logic of the 'base_columnDescription' tool. It executes a SQL query against DBC.ColumnsVX to retrieve detailed column information (name and decoded type) for tables/views matching the provided database_name and obj_name patterns (using LIKE with wildcards if empty). Returns formatted JSON data with metadata.def handle_base_columnDescription(conn: TeradataConnection, database_name: str | None, obj_name: str, *args, **kwargs): """ Shows detailed column information about a database table via SQLAlchemy, bind parameters if provided (prepared SQL), and return the fully rendered SQL (with literals) in metadata. Arguments: database_name - Database name obj_name - table or view name Returns: ResponseType: formatted response with query results + metadata """ logger.debug(f"Tool: handle_base_columnDescription: Args: database_name: {database_name}, obj_name: {obj_name}") if len(database_name) == 0: database_name = "%" if len(obj_name) == 0: obj_name = "%" with conn.cursor() as cur: query = """ sel TableName, ColumnName, CASE ColumnType WHEN '++' THEN 'TD_ANYTYPE' WHEN 'A1' THEN 'UDT' WHEN 'AT' THEN 'TIME' WHEN 'BF' THEN 'BYTE' WHEN 'BO' THEN 'BLOB' WHEN 'BV' THEN 'VARBYTE' WHEN 'CF' THEN 'CHAR' WHEN 'CO' THEN 'CLOB' WHEN 'CV' THEN 'VARCHAR' WHEN 'D' THEN 'DECIMAL' WHEN 'DA' THEN 'DATE' WHEN 'DH' THEN 'INTERVAL DAY TO HOUR' WHEN 'DM' THEN 'INTERVAL DAY TO MINUTE' WHEN 'DS' THEN 'INTERVAL DAY TO SECOND' WHEN 'DY' THEN 'INTERVAL DAY' WHEN 'F' THEN 'FLOAT' WHEN 'HM' THEN 'INTERVAL HOUR TO MINUTE' WHEN 'HR' THEN 'INTERVAL HOUR' WHEN 'HS' THEN 'INTERVAL HOUR TO SECOND' WHEN 'I1' THEN 'BYTEINT' WHEN 'I2' THEN 'SMALLINT' WHEN 'I8' THEN 'BIGINT' WHEN 'I' THEN 'INTEGER' WHEN 'MI' THEN 'INTERVAL MINUTE' WHEN 'MO' THEN 'INTERVAL MONTH' WHEN 'MS' THEN 'INTERVAL MINUTE TO SECOND' WHEN 'N' THEN 'NUMBER' WHEN 'PD' THEN 'PERIOD(DATE)' WHEN 'PM' THEN 'PERIOD(TIMESTAMP WITH TIME ZONE)' WHEN 'PS' THEN 'PERIOD(TIMESTAMP)' WHEN 'PT' THEN 'PERIOD(TIME)' WHEN 'PZ' THEN 'PERIOD(TIME WITH TIME ZONE)' WHEN 'SC' THEN 'INTERVAL SECOND' WHEN 'SZ' THEN 'TIMESTAMP WITH TIME ZONE' WHEN 'TS' THEN 'TIMESTAMP' WHEN 'TZ' THEN 'TIME WITH TIME ZONE' WHEN 'UT' THEN 'UDT' WHEN 'YM' THEN 'INTERVAL YEAR TO MONTH' WHEN 'YR' THEN 'INTERVAL YEAR' WHEN 'AN' THEN 'UDT' WHEN 'XM' THEN 'XML' WHEN 'JN' THEN 'JSON' WHEN 'DT' THEN 'DATASET' WHEN '??' THEN 'STGEOMETRY''ANY_TYPE' END as CType from DBC.ColumnsVX where upper(tableName) like upper(?) and upper(DatabaseName) like upper(?) """ rows = cur.execute(query, [obj_name, database_name]) data = rows_to_json(cur.description, rows.fetchall()) metadata = { "tool_name": "base_columnDescription", "database": database_name, "object": obj_name, "column_count": len(data) } logger.debug(f"Tool: handle_base_columnDescription: metadata: {metadata}") return create_response(data, metadata)
- src/teradata_mcp_server/app.py:270-281 (registration)Dynamic registration code that scans loaded modules for functions starting with 'handle_', derives the tool name by stripping the 'handle_' prefix (e.g., 'handle_base_columnDescription' -> 'base_columnDescription'), wraps the handler with connection injection and QueryBand support, and registers it as an MCP tool using FastMCP's mcp.tool decorator.module_loader = td.initialize_module_loader(config) if module_loader: all_functions = module_loader.get_all_functions() for name, func in all_functions.items(): if not (inspect.isfunction(func) and name.startswith("handle_")): continue tool_name = name[len("handle_"):] if not any(re.match(p, tool_name) for p in config.get('tool', [])): continue wrapped = make_tool_wrapper(func) mcp.tool(name=tool_name, description=wrapped.__doc__)(wrapped) logger.info(f"Created tool: {tool_name}")