# useDatabase() This operation sets the active database for the gRPC client. ```javascript useDatabase(data?): Promise ``` ## Request Syntax ```javascript milvusClient.useDatabase({ db_name: string }) ``` **PARAMETERS:** - **db_name** (*string*) - The name of the database to use. There should be a database with the specified name. Otherwise, exceptions will occur. **RETURNS** *Promise |<ResStatus>* This method returns a promise that resolves to a **ResStatus** object. ```javascript { code: number, error_code: string | number, reason: string } ``` **PARAMETERS:** - **code** (*number*) - A code that indicates the operation result. It remains **0** if this operation succeeds. - **error_code** (*string* | *number*) - An error code that indicates an occurred error. It remains **Success** if this operation succeeds. - **reason** (*string*) - The reason that indicates the reason for the reported error. It remains an empty string if this operation succeeds. ## Example ```javascript const milvusClient = new milvusClient(MILUVS_ADDRESS); const resStatus = await milvusClient.useDatabase({ db_name: 'new_db' }); ```