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

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.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哪个文档。

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分片化集合

Documents in a sharded collection can be missing the shard key fields. 分片集合中的文档可能缺少分片键字段。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). For example:要针对缺少分片键的文档，您可以将空相等匹配与另一个筛选条件结合使用（例如在_id字段上）。例如：

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

Transactions事务

db.collection.findOneAndDelete() 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，请参阅事务和写入关注。

Oplog Entries操作日志条目

If a db.collection.findOneAndDelete() operation successfully deletes a document, the operation adds an entry on the oplog (operations log). 如果db.collection.findOneAndDelete()操作成功删除文档，则该操作会在oplog（操作日志）上添加一个条目。If the operation fails or does not find a document to delete, the operation does not add an entry on the oplog.如果操作失败或找不到要删除的文档，则操作不会在oplog上添加条目。

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:以下操作找到名为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db.collection.findOneAndDelete()方法中使用带有选项的写关注文档：

• w:1 to requests acknowledgment that the write operation has propagated to the standalone mongod or the primary in a replica set.请求确认写入操作已传播到独立mongod或副本集中的主服务器。
• 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中指定的要将delete写入磁盘journel的MongoDB实例的数量。
• wtimeout : 1000 to specify a time limit, in milliseconds, for the write concern. wtimeout is only applicable for w values greater than 1.为写入关注指定时间限制（以毫秒为单位）。wtimeout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.使用指定的writeConcern选项删除文档。

Sort And Delete A Document排序和删除文档

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". It then sorts by points ascending before deleting the document with the lowest points value:以下操作首先查找name : "A. MacDyver"的所有文档。然后，在删除具有最低点值的文档之前，它按points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按时间限制更新文档

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

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.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：

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" }