Single document management APIs

The basic document CRUD APIs are targeted at a single document. Before we jump into those APIs, let's get familiar with our sample document first.

Sample documents

The contents of the sample documents describe the commission-free ETF. The list contains 314 ETFs provided by TD Ameritrade (https://research.tdameritrade.com/grid/public/etfs/commissionfree/commissionfree.asp). Each ETF has seven fixed fields and two optional fields. They are described in the following table:

Field name	Fixed/optional	Description
symbol	Fixed	The ticker symbol of the ETF.
fund_name	Fixed	The name of the ETF.
rating	Optional	The given risk rating to the ETF by Morningstar, with one star being the worst...