db.collection.remove() (mongosh method方法)

Write Concern写入关注

The remove() method uses the delete command, which uses the default write concern. To specify a different write concern, include the write concern in the options parameter.remove()方法使用delete命令，该命令使用默认的写入关注。要指定不同的写入关注，请将写入关注包含在options参数中。

Query Considerations查询注意事项

By default, remove() removes all documents that match the query expression. Specify the justOne option to limit the operation to removing a single document. 默认情况下，remove()会删除与query表达式匹配的所有文档。指定justOne选项以将操作限制为删除单个文档。To delete a single document sorted by a specified order, use the findAndModify() method.要删除按指定顺序排序的单个文档，请使用findAndModify()方法。

When removing multiple documents, the remove operation may interleave with other read and/or write operations to the collection.在删除多个文档时，删除操作可能会与对集合的其他读取和/或写入操作交织在一起。

Time Series Collections时间序列集合

You cannot use the remove() method on a time series collection.您不能在时间序列集合上使用remove()方法。

Sharded Collections分片化集合

To use remove() operations for a sharded collection that specify the justOne: true option:要对指定justOne: true选项的分片集合使用remove()操作：

• If you only target one shard, you can use a partial shard key in the query specification or,如果你只针对一个分片，你可以在查询规范中使用部分分片键，或者，
• You can provide the shard key or the _id field in the query specification.您可以在查询规范中提供分片键或_id字段。

Transactions事务

db.collection.remove() can be used inside distributed transactions.可以在分布式事务中使用。

Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.如果在事务中运行，则不要显式设置操作的写入关注。要对事务使用写关注，请参阅事务和写关注。

Remove All Documents from a Collection从集合中删除所有文档

To remove all documents in a collection, call the remove method with an empty query document {}. The following operation deletes all documents from the bios collection:若要删除集合中的所有文档，请使用空查询文档{}调用remove方法。以下操作将从集合中删除所有文档：

db.bios.remove( { } )

This operation is not equivalent to the drop() method.此操作并不等同于drop()方法。

To remove all documents from a collection, it may be more efficient to use the drop() method to drop the entire collection, including the indexes, and then recreate the collection and rebuild the indexes.要从集合中删除所有文档，使用drop()方法删除整个集合（包括索引），然后重新创建集合并重建索引可能更有效。

Remove All Documents that Match a Condition删除符合条件的所有文档

To remove the documents that match a deletion criteria, call the remove() method with the <query> parameter:要删除符合删除条件的文档，请使用<query>参数调用remove()方法：

The following operation removes all the documents from the collection products where qty is greater than 20:以下操作将从集合products中删除qty大于20的所有文档：

db.products.remove( { qty: { $gt: 20 } } )

Override Default Write Concern覆盖默认写入关注

The following operation to a replica set removes all the documents from the collection products where qty is greater than 20 and specifies a write concern of w: 2 with a wtimeout of 5000 milliseconds. This operation either returns after the write propagates to both the primary and one secondary, or times out after 5 seconds.以下对副本集的操作将从qty大于20的集合products中删除所有文档，并指定w:2的写入关注，wtimeout为5000毫秒。此操作要么在写入传播到主服务器和一个辅助服务器后返回，要么在5秒后超时。

db.products.remove(
    { qty: { $gt: 20 } },
    { writeConcern: { w: "majority", wtimeout: 5000 } }
)

Remove a Single Document that Matches a Condition删除符合条件的单个文档

To remove the first document that match a deletion criteria, call the remove method with the query criteria and the justOne parameter set to true or 1.要删除符合删除条件的第一个文档，请使用query条件调用remove方法，并将justOne参数设置为true或1。

The following operation removes the first document from the collection products where qty is greater than 20:以下操作将从qty大于20的集合products中删除第一个文档：

db.products.remove( { qty: { $gt: 20 } }, true )

Specify Collation指定排序规则

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.排序规则允许用户为字符串比较指定特定于语言的规则，例如字母大小写和重音标记的规则。

A collection myColl has the following documents:myColl集合有以下文件：

{ _id: 1, category: "café", status: "A" }
{ _id: 2, category: "cafe", status: "a" }
{ _id: 3, category: "cafE", status: "a" }

The following operation includes the collation option:以下操作包括排序规则选项：

db.myColl.remove(
   { category: "cafe", status: "A" },
   { collation: { locale: "fr", strength: 1 } }
)

Use Variables in let在let中使用变量

To define variables that you can access elsewhere in the command, use the let option.要定义可以在命令的其他地方访问的变量，请使用let选项。

Create a collection cakeFlavors:创建一个系列cakeFlavors：

db.cakeFlavors.insertMany( [
   { _id: 1, flavor: "chocolate" },
   { _id: 2, flavor: "strawberry" },
   { _id: 3, flavor: "cherry" }
] )

The following example defines a targetFlavor variable in let and uses the variable to delete the strawberry cake flavor:以下示例在let中定义了targetFlavor变量，并使用该变量删除草莓蛋糕风味：

db.cakeFlavors.remove(
   { $expr: { $eq: [ "$flavor", "$$targetFlavor" ] } },
   { let : { targetFlavor: "strawberry" } }
)

Successful Results成功的结果

The remove() returns a WriteResult() object that contains the status of the operation. remove()返回一个包含操作状态的WriteResult()对象。Upon success, the WriteResult() object contains information on the number of documents removed:成功后，WriteResult()对象包含有关删除的文档数量的信息：

WriteResult({ "nRemoved" : 4 })

Write Concern Errors写入关注错误

If the remove() method encounters write concern errors, the results include the WriteResult.writeConcernError field:如果remove()方法遇到写关注错误，则结果包括WriteResult.writeConcernError字段：

WriteResult({
  "nRemoved" : 7,
  "writeConcernError" : {
    "code" : 64,
    "codeName" : "WriteConcernTimeout",
    "errmsg" : "waiting for replication timed out",
    "errInfo" : {
      "wtimeout" : true,
      "writeConcern" : {
        "w" : "majority",
        "wtimeout" : 1,
        "provenance" : "getLastErrorDefaults"
      }
    }
  }
})

Errors Unrelated to Write Concern与书写入关注无关的错误

If the remove() method encounters a non-write concern error, the results include WriteResult.writeError field:如果remove()方法遇到非写入关注错误，则结果包括WriteResult.writeError字段：

WriteResult({
   "nRemoved" : 0,
   "writeError" : {
      "code" : 2,
      "errmsg" : "unknown top level operator: $invalidFieldName"
   }
})