Create a new Collection instance创建新的集合实例
The name of this collection此集合的名称
The name of the database this collection belongs to此集合所属的数据库的名称
The namespace of this collection, in the format 此集合的命名空间，格式为${this.dbName}.${this.collectionName}${this.dbName}.${this.collectionName}
The current readConcern of the collection. If not explicitly defined for this collection, will be inherited from the parent DB集合的当前问题。如果未为此集合显式定义，则将从父数据库继承
The current readPreference of the collection. If not explicitly defined for this collection, will be inherited from the parent DB集合的当前readPreference。如果未为此集合显式定义，则将从父数据库继承
The current writeConcern of the collection. If not explicitly defined for this collection, will be inherited from the parent DB集合的当前WriteCenter。如果未为此集合显式定义，则将从父数据库继承
Execute an aggregation framework pipeline against the collection, needs MongoDB >= 2.2针对集合执行聚合框架管道，需要MongoDB>=2.2
An array of aggregation pipelines to execute要执行的聚合管道数组
Optional settings for the command命令的可选设置
Perform a bulkWrite operation without a fluent API在没有fluent API的情况下执行批量写入操作
Legal operation types are合法的操作类型包括
{ insertOne: { document: { a: 1 } } }
{ updateOne: { filter: {a:2}, update: {$set: {a:2}}, upsert:true } }
{ updateMany: { filter: {a:2}, update: {$set: {a:2}}, upsert:true } }
{ updateMany: { filter: {}, update: {$set: {"a.$[i].x": 5}}, arrayFilters: [{ "i.x": 5 }]} }
{ deleteOne: { filter: {c:1} } }
{ deleteMany: { filter: {c:1} } }
{ replaceOne: { filter: {c:3}, replacement: {c:4}, upsert:true} }
Please note that raw operations are no longer accepted as of driver version 4.0.请注意，从驱动程序版本4.0起，不再接受原始操作。
If documents passed in do not contain the _id field, one will be added to each of the documents missing it by the driver, mutating the document. 如果传入的文档不包含_id字段，则驱动程序会在缺少该字段的每个文档中添加一个字段，从而改变文档。This behavior can be overridden by setting the forceServerObjectId flag.可以通过设置forceServerObjectId标志来覆盖此行为。
Bulk operations to perform要执行的批量操作
An estimated count of matching documents in the db to a filter.数据库中与筛选器匹配的文档的估计计数。
NOTE: This method has been deprecated, since it does not provide an accurate count of the documents in a collection. 此方法已被弃用，因为它不能提供集合中文档的准确计数。To obtain an accurate count of documents in the collection, use countDocuments. 要获得集合中文档的准确计数，请使用countDocuments。To obtain an estimated count of all documents in the collection, use estimatedDocumentCount.要获取集合中所有文档的估计计数，请使用estimatedDocumentCount。
Gets the number of documents matching the filter. 获取与筛选器匹配的文档数。For a fast count of the total documents in a collection see estimatedDocumentCount.有关集合中文档总数的快速计数，请参阅estimatedDocumentCount。
Note: When migrating from count to countDocuments the following query operators must be replaced:注意：从count迁移到countDocuments时，必须替换以下查询运算符：
| Operator | Replacement |
|---|---|
$where |
$expr |
$near |
$geoWithin with $center |
$nearSphere |
$geoWithin with $centerSphere |
Creates an index on the db and collection collection.在数据库和集合上创建索引。
The field name or index specification to create an index for要为其创建索引的字段名或索引规范
Creates multiple indexes in the collection, this method is only supported for MongoDB 2.6 or higher. 在集合中创建多个索引，只有MongoDB 2.6或更高版本才支持此方法。Earlier version of MongoDB will throw a command not supported error.早期版本的MongoDB将抛出不支持的命令错误。
Note: Unlike createIndex, this function takes in raw index specifications.：与createIndex不同，此函数接受原始索引规范。
Index specifications are defined here.这里定义了索引规范。
An array of index specifications to be created要创建的索引规范数组
Delete multiple documents from a collection从集合中删除多个文档
The filter used to select the documents to remove用于选择要删除的文档的筛选器
Delete a document from a collection从集合中删除文档
The filter used to select the document to remove用于选择要删除的文档的筛选器
The distinct command returns a list of distinct values for the given key across a collection.distinct命令返回集合中给定键的不同值列表。
Field of the document to find distinct values for要为其查找不同值的文档的字段
Drop the collection from the database, removing it permanently. 从数据库中删除集合，并将其永久删除。New accesses will create a new collection.新访问将创建一个新集合。
Drops an index from this collection.从此集合中删除索引。
Name of the index to drop.要删除的索引的名称。
Drops all indexes from this collection.删除此集合中的所有索引。
Gets an estimate of the count of documents in a collection using collection metadata.获取使用集合元数据的集合中文档计数的估计值。
Creates a cursor for a filter that can be used to iterate over results from MongoDB为可用于迭代MongoDB结果的筛选器创建光标
Fetches the first document that matches the filter获取与筛选器匹配的第一个文档
Find a document and delete it in one atomic operation. 查找文档并在一个原子操作中删除它。Requires a write lock for the duration of the operation.在操作期间需要写锁。
The filter used to select the document to remove用于选择要删除的文档的筛选器
Find a document and replace it in one atomic operation. Requires a write lock for the duration of the operation.查找文档并在一个原子操作中替换它。在操作期间需要写锁。
The filter used to select the document to replace用于选择要替换的文档的筛选器
The Document that replaces the matching document替换匹配文档的文档
Find a document and update it in one atomic operation. 查找文档并在一个原子操作中更新它。Requires a write lock for the duration of the operation.在操作期间需要写锁。
The filter used to select the document to update用于选择要更新的文档的筛选器
Update operations to be performed on the document更新要对文档执行的操作
Get the db scoped logger获取db范围的记录器
Checks if one or more indexes exist on the collection, fails on first non-existing index检查集合上是否存在一个或多个索引，在第一个不存在的索引上失败
One or more index names to check.要检查的一个或多个索引名。
Retrieves this collections index info.检索此集合索引信息。
Retrieve all the indexes on the collection.检索集合上的所有索引。
Initiate an In order bulk write operation. 启动订单批量写入操作。Operations will be serially executed in the order they are added, creating a new operation for each switch in types.操作将按添加顺序串行执行，为类型中的每个开关创建一个新操作。
Initiate an Out of order batch write operation. All operations will be buffered into insert/update/remove commands executed out of order.启动无序批写入操作。所有操作都将缓冲到按顺序执行的insert/update/remove命令中。
Inserts a single document or a an array of documents into MongoDB. 将单个文档或文档数组插入MongoDB。If documents passed in do not contain the _id field, one will be added to each of the documents missing it by the driver, mutating the document. 如果传入的文档不包含_id字段，则驱动程序会在缺少该字段的每个文档中添加一个字段，从而改变文档。This behavior can be overridden by setting the forceServerObjectId flag.可以通过设置forceServerObjectId标志来覆盖此行为。
The documents to insert要插入的文件
Optional settings for the command命令的可选设置
An optional callback, a Promise will be returned if none is provided一个可选的回调，如果没有提供，将返回一个承诺
Inserts an array of documents into MongoDB. 将文档数组插入MongoDB。If documents passed in do not contain the _id field, one will be added to each of the documents missing it by the driver, mutating the document. 如果传入的文档不包含_id字段，则驱动程序会在缺少该字段的每个文档中添加一个字段，从而改变文档。This behavior can be overridden by setting the forceServerObjectId flag.可以通过设置forceServerObjectId标志来覆盖此行为。
The documents to insert要插入的文件
Inserts a single document into MongoDB. 将单个文档插入MongoDB。If documents passed in do not contain the _id field, one will be added to each of the documents missing it by the driver, mutating the document. 如果传入的文档不包含_id字段，则驱动程序会在缺少该字段的每个文档中添加一个字段，从而改变文档。This behavior can be overridden by setting the forceServerObjectId flag.可以通过设置forceServerObjectId标志来覆盖此行为。
The document to insert要插入的文档
Returns if the collection is a capped collection如果集合是有上限的集合，则返回
Get the list of all indexes information for the collection.获取集合的所有索引信息的列表。
Optional settings for the command命令的可选设置
Run Map Reduce across a collection. Be aware that the inline option for out will return an array of results not a collection.跨集合运行Map Reduce。请注意，out的inline选项将返回结果数组，而不是集合。
The mapping function.
The reduce function.reduce函数。
Returns the options of the collection.返回集合的选项。
Remove documents.删除文档。
The selector for the update operation.更新操作的选择器。
Optional settings for the command命令的可选设置
An optional callback, a Promise will be returned if none is provided一个可选的回调，如果没有提供，将返回一个承诺
Rename the collection.重命名集合。
New name of of the collection.集合的新名称。
Replace a document in a collection with another document用另一个文档替换集合中的文档
The filter used to select the document to replace用于选择要替换的文档的筛选器
The Document that replaces the matching document替换匹配文档的文档
Get all the collection statistics.获取所有收集统计信息。
Updates documents.更新文档。
The selector for the update operation.更新操作的选择器。
The update operations to be applied to the documents要应用于文档的更新操作
Optional settings for the command命令的可选设置
An optional callback, a Promise will be returned if none is provided一个可选的回调，如果没有提供，将返回一个承诺
Update multiple documents in a collection更新集合中的多个文档
The filter used to select the documents to update用于选择要更新的文档的筛选器
The update operations to be applied to the documents要应用于文档的更新操作
Update a single document in a collection更新集合中的单个文档
The filter used to select the document to update用于选择要更新的文档的筛选器
The update operations to be applied to the document要应用于文档的更新操作
Create a new Change Stream, watching for new changes (insertions, updates, replacements, deletions, and invalidations) in this collection.创建新的更改流，监视此集合中的新更改（插入、更新、替换、删除和失效）。
An array of aggregation pipeline stages through which to pass change stream documents. 用于传递更改流文档的聚合管道阶段数组。This allows for filtering (using $match) and manipulating the change stream documents.这允许过滤（使用$match）和操作更改流文档。
Optional settings for the command命令的可选设置
The Collection class is an internal class that embodies a MongoDB collection allowing for insert/update/remove/find and other command operation on that MongoDB collection.Collection类是包含MongoDB集合的内部类，允许对该MongoDB集合执行插入、更新、删除、查找和其他命令操作。COLLECTION Cannot directly be instantiated集合不能直接实例化