可以通过对集合对象使用 ReplaceOne() 同步方法或 ReplaceOneAsync() 异步方法将一个文档替换为另一个文档。
例子
以下代码替换 restaurants 集合中 cuisine 字段值为“Pizza”的第一个文档。替换后，此文档将具有值为“Mongo's Pizza”的 name 字段以及 address 和 borough 字段的新值。
选择 Asynchronous 或 Synchronous 标签页，查看相应的代码。
// Creates a filter for all restaurant documents that have a "cuisine" value of "Pizza"var filter = Builders<Restaurant>.Filter .Eq(r => r.Cuisine, "Pizza");
// Finds the ID of the first restaurant document that matches the filtervar oldPizzaRestaurant = _restaurantsCollection.Find(filter).First();var oldId = oldPizzaRestaurant.Id;
// Generates a new restaurant documentRestaurant newPizzaRestaurant = new(){ Id = oldId, Name = "Mongo's Pizza", Cuisine = "Pizza", Address = new Address() { Street = "Pizza St", ZipCode = "10003" }, Borough = "Manhattan",};
// Asynchronously replaces the existing restaurant document with the new documentreturn await _restaurantsCollection.ReplaceOneAsync(filter, newPizzaRestaurant);有关 ReplaceOneAsync() 操作的完全可运行的示例，请参阅 ReplaceOneAsync 代码示例。
// Creates a filter for all restaurant documents that have a "cuisine" value of "Pizza"var filter = Builders<Restaurant>.Filter .Eq(r => r.Cuisine, "Pizza");
// Finds the ID of the first restaurant document that matches the filtervar oldPizzaRestaurant = _restaurantsCollection.Find(filter).First();var oldId = oldPizzaRestaurant.Id;
// Generates a new restaurant documentRestaurant newPizzaRestaurant = new(){ Id = oldId, Name = "Mongo's Pizza", Cuisine = "Pizza", Address = new Address() { Street = "Pizza St", ZipCode = "10003" }, Borough = "Manhattan",};
// Replaces the existing restaurant document with the new documentreturn _restaurantsCollection.ReplaceOne(filter, newPizzaRestaurant);有关 ReplaceOne() 操作的完全可运行示例，请参阅 ReplaceOne 代码示例。
预期结果
运行上述任一完整示例都会输出以下结果：
First pizza restaurant before replacement: J&V Famous PizzaRestaurants modified by replacement: 1First pizza restaurant after replacement: Mongo's PizzaResetting sample data...done.更多信息
如需了解有关使用生成器的更多信息，请参阅生成器操作。