What causes "can not use connection_name when create connection" in databendlabs/databend?

Remove CONNECTION_NAME from the inline CONNECTION options in CREATE CONNECTION

can not use connection_name when create connection

Error message

can not use connection_name when create connection

What it means

parse_uri_location builds storage params directly from inline CONNECTION options and a URI, so referencing a named connection (connection_name) is meaningless and disallowed there. If the connection options include connection_name while creating a connection or resolving a URI location, this InvalidInput error is thrown.

Solutions

Remove CONNECTION_NAME from the inline CONNECTION options in CREATE CONNECTION
Specify the actual storage options (endpoint_url, credentials, etc.) inline instead
Use the named connection where allowed (e.g. in stage definitions), not when creating a connection

Example fix

-- before
CREATE CONNECTION c CONNECTION=(CONNECTION_NAME='prod_s3');
-- after
CREATE CONNECTION c STORAGE_TYPE='s3' ENDPOINT_URL='https://s3.amazonaws.com';

Defensive patterns

Strategy: validation

Validate before calling

if opts.contains_key("connection_name") && is_create_connection_ddl {
    return Err("CONNECTION_NAME cannot be used inside CREATE CONNECTION".into());
}

Try / catch

match err.kind() { ErrorKind::InvalidInput if msg.contains("can not use connection_name") => /* strip CONNECTION_NAME and inline real options */, _ => return Err(err) }

Prevention

Never nest CONNECTION_NAME inside CREATE CONNECTION
Use named connections only where supported (stage definitions)
Generate DDL from templates that exclude connection_name for create-connection paths

When it happens

Trigger: CREATE CONNECTION ... CONNECTION=(CONNECTION_NAME='other') — nesting a connection reference inside connection creation; passing a connection_name option in a stage/connection DDL that resolves URI options inline.

Common situations: Confusing named-connection usage (USE CONNECTION / CONNECTION_NAME on stages) with CREATE CONNECTION DDL; templated SQL that always injects CONNECTION_NAME.

Related errors

AI-assisted analysis of databendlabs/databend@288d84d76e (2026-09-11). Data as JSON: /api/errors/af77b7185acbebab. Report an issue: GitHub.

Appendix: source

Thrown at src/query/sql/src/planner/binder/location.rs:549

            ErrorKind::InvalidInput,
            anyhow!("protocol {protocol} is not supported yet."),
        ));
    }

    Ok(ParsedUriLocation {
        root,
        path,
        protocol,
    })
}

pub async fn parse_uri_location(l: &mut UriLocation) -> Result<(StorageParams, String)> {
    let parts = parse_uri_location_parts(l)?;

    if l.connection.get("connection_name").is_some() {
        return Err(Error::new(
            ErrorKind::InvalidInput,
            anyhow!("can not use connection_name when create connection"),
        ));
    }

    parse_uri_location_resolved(l, parts).await
}

pub fn apply_uri_connection(
    l: &mut UriLocation,
    name: &str,
    conn: UserDefinedConnection,
) -> Result<()> {
    let protocol = l.protocol.parse::<Scheme>()?;
    let proto = conn.storage_type.parse::<Scheme>().map_err(|err| {
        Error::new(
            ErrorKind::InvalidInput,
            anyhow!("input connection is not a valid protocol: {err:?}"),
        )
    })?;

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