db.collection.findOneAndDelete()

Document Match文档匹配

findOneAndDelete() deletes the first matching document in the collection that matches the filter. The sort parameter can be used to influence which document is deleted.findOneAndDelete()删除集合中与filter匹配的第一个匹配文档。sort参数可用于影响删除的文档。

Projection投影

The projection parameter takes a document in the following form:projection参数采用以下形式的文档：

{ field1: <value>, field2: <value> ... }

Sharded Collections分片集合

When using db.collection.findOneAndDelete() against a sharded collection, the query must contain an equality condition on shard key.对分片集合使用db.collection.findOneAndDelete()时，query必须包含分片键上的相等条件。

Starting in version 4.4, documents in a sharded collection can be missing the shard key fields. 从4.4版本开始，分片集合中的文档可能会缺少分片键字段。To target a document that is missing the shard key, you can use the null equality match in conjunction with another filter condition (such as on the _id field). 要针对缺少分片键的文档，可以将null相等匹配与另一个筛选条件结合使用（例如在_id字段上）。For example:例如：

{ _id: <value>, <shardkeyfield>: null } // _id of the document missing shard key

Transactions事务

db.collection.findOneAndDelete() can be used inside multi-document transactions.可以在多文档事务中使用。

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，请不要显式设置操作的写入关注。要在事务中使用写入关注，请参阅事务和写入关注。

Delete A Document删除文档

The scores collection contains documents similar to the following:scores集合包含类似于以下内容的文档：

 db.scores.insertMany( [
   { _id: 6305, name : "A. MacDyver", "assignment" : 5, "points" : 24 },
   { _id: 6308, name : "B. Batlock", "assignment" : 3, "points" : 22 },
   { _id: 6312, name : "M. Tagnum", "assignment" : 5, "points" : 30 },
   { _id: 6319, name : "R. Stiles", "assignment" : 2, "points" : 12 },
   { _id: 6322, name : "A. MacDyver", "assignment" : 2, "points" : 14 },
   { _id: 6234, name : "R. Stiles", "assignment" : 1, "points" : 10 }
] )

The following operation finds the first document where name : M. Tagnum and deletes it:以下操作将查找name : M. Tagnum的第一个文档并将其删除：

db.scores.findOneAndDelete(
   { "name" : "M. Tagnum" }
)

The operation returns the original document that has been deleted:该操作返回已删除的原始文档：

{ _id: 6312, name: "M. Tagnum", "assignment" : 5, "points" : 30 }

Delete A Document Using WriteConcern使用WriteConcern删除文档

The scores collection contains documents similar to the following:scores集合包含类似于以下内容的文档：

db.scores.insertMany( [
   { _id: 6305, name : "A. MacDyver", "assignment" : 5, "points" : 24 },
   { _id: 6308, name : "B. Batlock", "assignment" : 3, "points" : 22 },
   { _id: 6312, name : "M. Tagnum", "assignment" : 5, "points" : 30 },
   { _id: 6319, name : "R. Stiles", "assignment" : 2, "points" : 12 },
   { _id: 6322, name : "A. MacDyver", "assignment" : 2, "points" : 14 },
   { _id: 6234, name : "R. Stiles", "assignment" : 1, "points" : 10 }
] )

The following operation uses a write concern document inside of the db.collection.findOneAndDelete() method with options:以下操作在带有选项的db.collection.findOneAndDelete()方法内部使用一个写入关注文档：

• w:1 to requests acknowledgment that the write operation has propagated to the standalone mongod or the primary in a replica set.用来请求确认写入操作已传播到副本集中的独立mongod或主mongod。
• j:true to tell the number of MongoDB instances specified in w:1 to have the delete written to on-disk journel.告诉w:1中指定的要在磁盘journel上写入删除的MongoDB实例的数量。
• wtimeout : 1000 to specify a time limit, in milliseconds, for the write concern. 指定写入关注的时间限制（以毫秒为单位）。wtimeout is only applicable for w values greater than 1.仅适用于大于1的w值。

db.scores.findOneAndDelete(
   { name: "A. MacDyver" },
   {
      writeConcern: {
         w : 1,
         j : true,
         wtimeout : 1000
      }
   }
)

The operation returns the following document:该操作返回以下文档：

{ _id: 6305, name: 'A. MacDyver', assignment: 5, points: 24 }

The document is deleted with the writeConcern options specified.删除文档时指定了writeConcern选项。

Sort And Delete A Document排序并删除文档

The scores collection contains documents similar to the following:scores集合包含类似于以下内容的文档：

db.scores.insertMany( [
   { _id: 6305, name : "A. MacDyver", "assignment" : 5, "points" : 24 },
   { _id: 6308, name : "B. Batlock", "assignment" : 3, "points" : 22 },
   { _id: 6312, name : "M. Tagnum", "assignment" : 5, "points" : 30 },
   { _id: 6319, name : "R. Stiles", "assignment" : 2, "points" : 12 },
   { _id: 6322, name : "A. MacDyver", "assignment" : 2, "points" : 14 },
   { _id: 6234, name : "R. Stiles", "assignment" : 1, "points" : 10 }
] )

The following operation first finds all documents where name : "A. MacDyver". 以下操作首先查找name : "A. MacDyver"的所有文档。It then sorts by points ascending before deleting the document with the lowest points value:然后，在删除点值最低的文档之前，它会按升序排序：

db.scores.findOneAndDelete(
   { "name" : "A. MacDyver" },
   { sort : { "points" : 1 } }
)

The operation returns the original document that has been deleted:该操作返回已删除的原始文档：

{ _id: 6322, name: "A. MacDyver", "assignment" : 2, "points" : 14 }

Projecting the Deleted Document投影已删除的文档

The following operation uses projection to only return the _id and assignment fields in the returned document:以下操作使用投影仅返回返回文档中的_id和assignment字段：

db.scores.findOneAndDelete(
   { "name" : "A. MacDyver" },
   { sort : { "points" : 1 }, projection: { "assignment" : 1 } }
)

The operation returns the original document with the assignment and _id fields:该操作返回带有assignment和_id字段的原始文档：

{ _id: 6322, "assignment" : 2 }

Update Document with Time Limit更新有时限的文档

The following operation sets a 5ms time limit to complete the deletion:以下操作设置5ms的时间限制以完成删除：

try {
   db.scores.findOneAndDelete(
      { "name" : "A. MacDyver" },
      { sort : { "points" : 1 }, maxTimeMS : 5 }
   )
}
catch(e){
   print(e)
}

If the operation exceeds the time limit, it returns:如果操作超过时间限制，则返回：

MongoServerError: operation exceeded time limit: { "ok": 0, "code" : 50, "codeName" : "MaxTimeMSExpired" }

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.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:集合myColl包含以下文档：

db.myColl.insertMany( [
   { _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collation选项：

db.myColl.findOneAndDelete(
   { category: "cafe", status: "a" },
   { collation: { locale: "fr", strength: 1 } }
);

The operation returns the following document:该操作返回以下文档：

{ "_id" : 1, "category" : "café", "status" : "A" }