查询空字段或缺少字段

This page provides examples of operations that query for null values using MongoDB Compass. The examples on this page use the inventory collection. Populate the inventory collection with the following documents:

[
   { _id: 1, item: null },
   { _id: 2 }
]

For instructions on inserting documents in MongoDB Compass, see Insert Documents.

This page provides examples of operations that query for null values using the pymongo.collection.Collection.find() method in the PyMongo Python driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

db.inventory.insert_many([{"_id": 1, "item": None}, {"_id": 2}])

This page provides examples of operations that query for null values using the com.mongodb.client.MongoCollection.find method in the MongoDB Java Synchronous Driver.

The examples on this page use the inventory collection. To populate the inventory collection, run the following:

collection.insertMany(asList(
        Document.parse("{'_id': 1, 'item': null}"),
        Document.parse("{'_id': 2}")
));

This page provides examples of operations that query for null values using the Collection.find() method in the MongoDB Node.js Driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

await db.collection('inventory').insertMany([{ _id: 1, item: null }, { _id: 2 }]);

This page provides examples of operations that query for null values using the MongoDB\Collection::find() method in the MongoDB PHP Library. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

$insertManyResult = $db->inventory->insertMany([
    ['_id' => 1, 'item' => null],
    ['_id' => 2],
]);

This page provides examples of operations that query for null values using the motor.motor_asyncio.AsyncIOMotorCollection.find() method in the Motor driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

await db.inventory.insert_many([{"_id": 1, "item": None}, {"_id": 2}])

This page provides examples of operations that query for null values using the com.mongodb.reactivestreams.client.MongoCollection.find method in the MongoDB Java Reactive Streams Driver.

The examples on this page use the inventory collection. To populate the inventory collection, run the following:

Publisher<Success> insertManyPublisher = collection.insertMany(asList(
        Document.parse("{'_id': 1, 'item': null}"),
        Document.parse("{'_id': 2}")
));

This page provides examples of operations that query for null values using the MongoCollection.Find() method in the MongoDB C# Driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

var documents = new[]
{
    new BsonDocument { { "_id", 1 }, { "item", BsonNull.Value } },
    new BsonDocument { { "_id", 2 } }
};
collection.InsertMany(documents);

This page provides examples of operations that query for null values using the MongoDB::Collection::find() method in the MongoDB Perl Driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

$db->coll("inventory")->insert_many( [ { _id => 1, item => undef }, { _id => 2 } ] );

This page provides examples of operations that query for null values using the Mongo::Collection#find() method in the MongoDB Ruby Driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

client[:inventory].insert_many([{ _id: 1, item: nil },
                                { _id: 2 }])

This page provides examples of operations that query for null values using the collection.find() method in the MongoDB Scala Driver. The examples on this page use the inventory collection. To populate the inventory collection, run the following:

collection.insertMany(Seq(
  Document("""{"_id": 1, "item": null}"""),
  Document("""{"_id": 2}""")
)).execute()

The { item : null } query matches documents that either contain the item field whose value is null or that do not contain the item field.
Copy the following query filter document into the query bar and click Find:

{ item: null }

The { item : None } query matches documents that either contain the item field whose value is null or that do not contain the item field.

cursor = db.inventory.find({"item": None})

The eq("item", null) query matches documents that either contain the item field whose value is null or that do not contain the item field.

FindIterable<Document> findIterable = collection.find(eq("item", null));

The { item : null } query matches documents that either contain the item field whose value is null or that do not contain the item field.

const cursor = db.collection('inventory').find({
  item: null
});

The [ item => undef ] query matches documents that either contain the item field whose value is null or that do not contain the item field.

$cursor = $db->inventory->find(['item' => null]);

The { item : None } query matches documents that either contain the item field whose value is null or that do not contain the item field.

cursor = db.inventory.find({"item": None})

The eq("item", null) query matches documents that either contain the item field whose value is null or that do not contain the item field.

FindPublisher<Document> findPublisher = collection.find(eq("item", null));

The Eq("item", BsonNull.Value) query using the FilterDefinitionBuilder.Eq() method matches documents that either contain the item field whose value is null or that do not contain the item field.

var filter = Builders<BsonDocument>.Filter.Eq("item", BsonNull.Value);
var result = collection.Find(filter).ToList();

The { item => undef } query matches documents that either contain the item field whose value is null or that do not contain the item field.

$cursor = $db->coll("inventory")->find( { item => undef } );

The { item => nil } query matches documents that either contain the item field whose value is nil or that do not contain the item field.

client[:inventory].find(item: nil)

The equal("item", BsonNull) query matches documents that either contain the item field whose value is null or that do not contain the item field.

var findObservable = collection.find(equal("item", BsonNull()))

The { item : { $type: 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :
Copy the following query filter document into the query bar and click Find:

{ item : { $type: 10 } }

The { item : { $type: 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

cursor = db.inventory.find({"item": {"$type": 10}})

The type("item", BsonType.NULL) query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

findIterable = collection.find(type("item", BsonType.NULL));

The { item : { $type: 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

const cursor = db.collection('inventory').find({
  item: { $type: 10 }
});

The [ item => [ $type => 10 ] ] query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

$cursor = $db->inventory->find(['item' => ['$type' => 10]]);

The { item : { $type: 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

cursor = db.inventory.find({"item": {"$type": 10}})

The type("item", BsonType.NULL) query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

findPublisher = collection.find(type("item", BsonType.NULL));

The Type("item", BsonType.Null) query using the FilterDefinitionBuilder.Type() method matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

var filter = Builders<BsonDocument>.Filter.Type("item", BsonType.Null);
var result = collection.Find(filter).ToList();

The { item => { $type => 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

$cursor = $db->coll("inventory")->find( { item => { '$type' => 10 } } );

The { item => { $type => 10 } } query matches only documents that contain the item field whose value is null ; i.e. the value of the item field is of BSON Type Null (type number 10 ) :

client[:inventory].find(item: { '$type' => 10 })

findObservable = collection.find(bsonType("item", BsonType.NULL))

The { item : { $exists: false } } query matches documents that do not contain the item field:
Copy the following query filter document into the query bar and click Find:

{ item : { $exists: false } }

The { item : { $exists: False } } query matches documents that do not contain the item field:

cursor = db.inventory.find({"item": {"$exists": False}})

The exists("item", false) query matches documents that do not contain the item field:

findIterable = collection.find(exists("item", false));

The { item : { $exists: false } } query matches documents that do not contain the item field:

const cursor = db.collection('inventory').find({
  item: { $exists: false }
});

The [ item => [ $exists => false ] ] query matches documents that do not contain the item field:

$cursor = $db->inventory->find(['item' => ['$exists' => false]]);

The { item : { $exists: False } } query matches documents that do not contain the item field:

cursor = db.inventory.find({"item": {"$exists": False}})

The exists("item", false) query matches documents that do not contain the item field:

findPublisher = collection.find(exists("item", false));

The Exists("item", false) query using the FilterDefinitionBuilder.Exists() method matches documents that do not contain the item field:

var filter = Builders<BsonDocument>.Filter.Exists("item", false);
var result = collection.Find(filter).ToList();

The { item => { $exists => false } } query matches documents that do not contain the item field:

# For boolean values, use boolean.pm for 'true' and 'false'
$cursor = $db->coll("inventory")->find( { item => { '$exists' => false } } );

The { item => { $exists => false } } query matches documents that do not contain the item field:

client[:inventory].find(item: { '$exists' => false })

The exists("item", exists = false) query matches documents that do not contain the item field:

findObservable = collection.find(exists("item", exists = false))