db.collection.findOneAndUpdate()¶

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Definition
Behavior

Definition¶

db.collection.findOneAndUpdate(filter, update, options)¶

3.2 新版功能.

Updates a single document based on the filter and sort criteria.

The findOneAndUpdate() method has the following form:

db.collection.findOneAndUpdate(
   <filter>,
   <update>,
   {
     projection: <document>,
     sort: <document>,
     maxTimeMS: <number>,
     upsert: <boolean>,
     returnNewDocument: <boolean>,
     collation: <document>
   }
)

The findOneAndUpdate() method takes the following parameters:

Parameter	Type	Description
`filter`	document	The selection criteria for the update. The same query selectors as in the `find()` method are available. Specify an empty document `{ }` to update the first document returned in the collection.
`update`	document	The update document. Must contain only update operators.
`projection`	document	Optional. A subset of fields to return. To return all fields in the returned document, omit this parameter.
`sort`	document	Optional. Specifies a sorting order for the documents matched by the `filter`. See `cursor.sort()`.
`maxTimeMS`	number	Optional. Specifies a time limit in milliseconds within which the operation must complete within. Throws an error if the limit is exceeded.
`upsert`	boolean	Optional. When `true`, `findOneAndUpdate()` either: Creates a new document if no documents match the `filter`. For more details see upsert behavior. Returns `null` after inserting the new document, unless `returnNewDocument` is `true`. Updates a single document that matches the `filter`. To avoid multiple upserts, ensure that the `filter` fields are uniquely indexed. Defaults to `false`.
`returnNewDocument`	boolean	Optional. When `true`, returns the updated document instead of the original document. Defaults to `false`.
`collation`	document	Optional. Specifies the collation to use for the operation. Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. The collation option has the following syntax: collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> } When specifying collation, the `locale` field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document. If the collation is unspecified but the collection has a default collation (see `db.createCollection()`), the operation uses the collation specified for the collection. If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons. 3.4 新版功能.

返回:	Returns either the original document or, if `returnNewDocument: true`, the updated document.

Behavior¶

findOneAndUpdate() updates the first matching document in the collection that matches the filter. The sort parameter can be used to influence which document is updated.

The projection parameter takes a document in the following form:

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

The <boolean> value can be any of the following:

1 or true to include the field. The method returns the _id field even if it is not explicitly stated in the projection parameter.
0 or false to exclude the field. This can be used on any field, including _id.

Examples¶

Update A Document¶

The grades collection contains documents similar to the following:

{ _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 : R. Stiles and increments the score by 5:

db.scores.findOneAndUpdate(
   { "name" : "R. Stiles" },
   { $inc: { "points" : 5 } }
)

The operation returns the original document before the update:

{ _id: 6319, name: "R. Stiles", "assignment" : 2, "points" : 12 }

If returnNewDocument was true, the operation would return the updated document instead.

Sort And Update A Document¶

The grades collection contains documents similar to the following:

{ _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 updates a document where name : "A. MacGyver". The operation sorts the matching documents by points ascending to update the matching document with the least points.

db.scores.findOneAndUpdate(
   { "name" : "A. MacDyver" },
   { $inc : { "points" : 5 } },
   { sort : { "points" : 1 } }
)

The operation returns the original document before the update:

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

Project the Returned Document¶

The following operation uses projection to only display the _id, points, and assignment fields in the returned document:

db.scores.findOneAndUpdate(
   { "name" : "A. MacDyver" },
   { $inc : { "points" : 5 } },
   { sort : { "points" : 1 }, projection: { "assignment" : 1, "points" : 1 } }
)

The operation returns the original document with only the fields specified in the projection document and the _id field as it was not explicitly suppressed (_id: 0) in the projection document.

{ "_id" : 6322, "assignment" : 2, "points" : 14 }

Update Document with Time Limit¶

The following operation sets a 5ms time limit to complete the update:

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

If the operation exceeds the time limit, it returns:

Error: findAndModifyFailed failed: { "ok" : 0, "errmsg" : "operation exceeded time limit", "code" : 50 }

Update Document with Upsert¶

The following operation uses the upsert field to insert the update document if nothing matches the filter:

try {
db.scores.findOneAndUpdate(
   { "name" : "A.B. Abracus" },
   { $set: { "name" : "A.B. Abracus", "assignment" : 5}, $inc : { "points" : 5 } },
   { sort: { "points" : 1 }, upsert:true, returnNewDocument : true }
);
}
catch (e){
   print(e);
}

The operation returns the following:

{
   "_id" : ObjectId("5789249f1c49e39a8adc479a"),
   "name" : "A.B. Abracus",
   "assignment" : 5,
   "points" : 5
}

If returnNewDocument was false, the operation would return null as there is no original document to return.

Specify Collation¶

3.4 新版功能.

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

A collection myColl has the following documents:

{ _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:

db.myColl.findOneAndUpdate(
   { category: "cafe" },
   { $set: { status: "Updated" } },
   { collation: { locale: "fr", strength: 1 } }
);

The operation returns the following document:

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

← db.collection.findOneAndReplace() db.collection.getIndexes() →