Query Documents查询文档¶

Select All Documents in a Collection选择集合中的所有文档¶

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
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db.inventory.find( {} )

cursor = db.inventory.find({})

FindIterable<Document> findIterable = collection.find(new Document());

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

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

cursor = db.inventory.find({})

FindPublisher<Document> findPublisher = collection.find(new Document());

var filter = Builders<BsonDocument>.Filter.Empty;
var result = collection.Find(filter).ToList();

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

client[:inventory].find({})

var findObservable = collection.find(Document())

cursor, err := coll.Find(
	context.Background(),
	bson.D{},
)

This operation corresponds to the following SQL statement:此操作对应于以下SQL语句：

SELECT * FROM inventory

Specify Equality Condition指定相等条件¶

{ <field1>: <value1>, ... }

{ <field1>: <value1>, ... }

{ <field1>: <value1>, ... }

and(eq( <field1>, <value1>), eq( <field2>, <value2>) ...)

{ <field1>: <value1>, ... }

[ <field1> => <value1>, ... ]

{ <field1>: <value1>, ... }

and(eq( <field1>, <value1>), eq( <field2>, <value2>) ...)

Builders<BsonDocument>.Filter.Eq(<field>, <value>);

{ <field1> => <value1>, ... }

{ <field1> => <value1>, ... }

and(equal(<field1>, <value1>), equal(<field2>, <value2>) ...)

The following example selects from the inventory collection all documents where the status equals "D":以下示例从inventory集合中选择status为"D"的所有文档：

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
  • PHP
  • Motor
  • Java (Async)
  • C#
  • Perl
  • Ruby
  • Scala
  • Go

db.inventory.find( { status: "D" } )

Copy the following filter into the Compass query bar and click Find:将以下过滤器复制到Compass查询栏中，然后单击“查找”：

{ status: "D" }

cursor = db.inventory.find({"status": "D"})

findIterable = collection.find(eq("status", "D"));

const cursor = db.collection('inventory').find({ status: 'D' });

$cursor = $db->inventory->find(['status' => 'D']);

cursor = db.inventory.find({"status": "D"})

findPublisher = collection.find(eq("status", "D"));

var filter = Builders<BsonDocument>.Filter.Eq("status", "D");
var result = collection.Find(filter).ToList();

$cursor = $db->coll("inventory")->find( { status => "D" } );

client[:inventory].find(status: 'D')

findObservable = collection.find(equal("status", "D"))

cursor, err := coll.Find(
	context.Background(),
	bson.D{{"status", "D"}},
)

This operation corresponds to the following SQL statement:此操作对应于以下SQL语句：

SELECT * FROM inventory WHERE status = "D"

Specify Conditions Using Query Operators使用查询运算符指定条件¶

{ <field1>: { <operator1>: <value1> }, ... }

{ <field1>: { <operator1>: <value1> }, ... }

{ <field1>: { <operator1>: <value1> }, ... }

and(gte(<field1>, <value1>), lt(<field2>, <value2>), eq(<field3>, <value3>))

{ <field1>: { <operator1>: <value1> }, ... }

[ <field1> => [ <operator1> => <value1> ], ... ]

{ <field1>: { <operator1>: <value1> }, ... }

and(gte(<field1>, <value1>), lt(<field2>, <value2>), eq(<field3>, <value3>))

var builder = Builders<BsonDocument>.Filter;
builder.And(builder.Eq(<field1>, <value1>), builder.Lt(<field2>, <value2>));

{ <field1> => { <operator1> => <value1> }, ... }

{ <field1> => { <operator1> => <value1> }, ... }

and(gte(<field1>, <value1>), lt(<field2>, <value2>), equal(<field3>, <value3>))

The following example retrieves all documents from the inventory collection where status equals either "A" or "D":以下示例从inventory集合中检索status为"A"或"D"的所有文档：

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
  • PHP
  • Motor
  • Java (Async)
  • C#
  • Perl
  • Ruby
  • Scala
  • Go

db.inventory.find( { status: { $in: [ "A", "D" ] } } )

Copy the following filter into the Compass query bar and click Find:将以下过滤器复制到Compass查询栏中，然后单击“查找”：

{ status: { $in: [ "A", "D" ] } }

cursor = db.inventory.find({"status": {"$in": ["A", "D"]}})

findIterable = collection.find(in("status", "A", "D"));

const cursor = db.collection('inventory').find({
  status: { $in: ['A', 'D'] }
});

$cursor = $db->inventory->find(['status' => ['$in' => ['A', 'D']]]);

cursor = db.inventory.find({"status": {"$in": ["A", "D"]}})

findPublisher = collection.find(in("status", "A", "D"));

var filter = Builders<BsonDocument>.Filter.In("status", new[] { "A", "D" });
var result = collection.Find(filter).ToList();

$cursor = $db->coll("inventory")->find( { status => { '$in' => [ "A", "D" ] } } );

client[:inventory].find(status: { '$in' => [ 'A', 'D' ]})

findObservable = collection.find(in("status", "A", "D"))

cursor, err := coll.Find(
	context.Background(),
	bson.D{{"status", bson.D{{"$in", bson.A{"A", "D"}}}}})

The operation corresponds to the following SQL statement:该操作对应于以下SQL语句：

SELECT * FROM inventory WHERE status in ("A", "D")

Refer to the Query and Projection Operators document for the complete list of MongoDB query operators.有关MongoDB查询运算符的完整列表，请参阅查询和投影运算符文档。

Specify AND Conditions规定AND条件¶

A compound query can specify conditions for more than one field in the collection’s documents. 复合查询可以为集合文档中的多个字段指定条件。Implicitly, a logical AND conjunction connects the clauses of a compound query so that the query selects the documents in the collection that match all the conditions.逻辑AND连词隐式地连接复合查询的子句，以便查询选择集合中匹配所有条件的文档。

The following example retrieves all documents in the inventory collection where the status equals "A" and qty is less than ($lt) 30:以下示例检索inventory集合中status为"A"且qty小于（$lt）30的所有文档：

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
  • PHP
  • Motor
  • Java (Async)
  • C#
  • Perl
  • Ruby
  • Scala
  • Go

db.inventory.find( { status: "A", qty: { $lt: 30 } } )

Copy the following filter into the Compass query bar and click Find:将以下过滤器复制到Compass查询栏中，然后单击“查找”：

{ status: "A", qty: { $lt: 30 } }

cursor = db.inventory.find({"status": "A", "qty": {"$lt": 30}})

findIterable = collection.find(and(eq("status", "A"), lt("qty", 30)));

const cursor = db.collection('inventory').find({
  status: 'A',
  qty: { $lt: 30 }
});

$cursor = $db->inventory->find([
    'status' => 'A',
    'qty' => ['$lt' => 30],
]);

cursor = db.inventory.find({"status": "A", "qty": {"$lt": 30}})

findPublisher = collection.find(and(eq("status", "A"), lt("qty", 30)));

var builder = Builders<BsonDocument>.Filter;
var filter = builder.And(builder.Eq("status", "A"), builder.Lt("qty", 30));
var result = collection.Find(filter).ToList();

$cursor = $db->coll("inventory")->find( { status => "A", qty => { '$lt' => 30 } } );

client[:inventory].find(status: 'A', qty: { '$lt' => 30 })

findObservable = collection.find(and(equal("status", "A"), lt("qty", 30)))

cursor, err := coll.Find(
	context.Background(),
	bson.D{
		{"status", "A"},
		{"qty", bson.D{{"$lt", 30}}},
	})

The operation corresponds to the following SQL statement:该操作对应于以下SQL语句：

SELECT * FROM inventory WHERE status = "A" AND qty < 30

See comparison operators for other MongoDB comparison operators.有关其他MongoDB比较运算符，请参阅比较运算符。

Specify OR Conditions规定OR条件¶

Using the $or operator, you can specify a compound query that joins each clause with a logical OR conjunction so that the query selects the documents in the collection that match at least one condition.使用$or运算符，可以指定一个复合查询，将每个子句与逻辑OR连接起来，以便查询选择集合中至少符合一个条件的文档。

The following example retrieves all documents in the collection where the status equals "A" or qty is less than ($lt) 30:以下示例检索集合中status等于"A"或qty小于（$lt）30的所有文档：

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
  • PHP
  • Motor
  • Java (Async)
  • C#
  • Perl
  • Ruby
  • Scala
  • Go

db.inventory.find( { $or: [ { status: "A" }, { qty: { $lt: 30 } } ] } )

Copy the following filter into the Compass query bar and click Find:将以下过滤器复制到Compass查询栏中，然后单击“查找”：

{ $or: [ { status: "A" }, { qty: { $lt: 30 } } ] }

cursor = db.inventory.find(
    {"$or": [{"status": "A"}, {"qty": {"$lt": 30}}]})

findIterable = collection.find(or(eq("status", "A"), lt("qty", 30)));

const cursor = db.collection('inventory').find({
  $or: [{ status: 'A' }, { qty: { $lt: 30 } }]
});

$cursor = $db->inventory->find([
    '$or' => [
        ['status' => 'A'],
        ['qty' => ['$lt' => 30]],
    ],
]);

cursor = db.inventory.find(
    {"$or": [{"status": "A"}, {"qty": {"$lt": 30}}]})

findPublisher = collection.find(or(eq("status", "A"), lt("qty", 30)));

var builder = Builders<BsonDocument>.Filter;
var filter = builder.Or(builder.Eq("status", "A"), builder.Lt("qty", 30));
var result = collection.Find(filter).ToList();

$cursor = $db->coll("inventory")->find(
    { '$or' => [ { status => "A" }, { qty => { '$lt' => 30 } } ] }
);

client[:inventory].find('$or' => [{ status: 'A' },
                                  { qty: { '$lt' => 30 } }
                                 ])

findObservable = collection.find(or(equal("status", "A"), lt("qty", 30)))

cursor, err := coll.Find(
	context.Background(),
	bson.D{
		{"$or",
			bson.A{
				bson.D{{"status", "A"}},
				bson.D{{"qty", bson.D{{"$lt", 30}}}},
			}},
	})

The operation corresponds to the following SQL statement:该操作对应于以下SQL语句：

SELECT * FROM inventory WHERE status = "A" OR qty < 30

Specify AND as well as OR Conditions指定AND以及OR条件¶

In the following example, the compound query document selects all documents in the collection where the status equals "A" and either qty is less than ($lt) 30 or item starts with the character p:在以下示例中，复合查询文档选择集合中status为"A"且qty小于（$lt）30或item以字符p开头的所有文档：

• Mongo Shell
• Compass
• Python
• Java (Sync)
• Node.js
• Other
  • PHP
  • Motor
  • Java (Async)
  • C#
  • Perl
  • Ruby
  • Scala
  • Go

db.inventory.find( {
     status: "A",
     $or: [ { qty: { $lt: 30 } }, { item: /^p/ } ]
} )

Copy the following filter into the Compass query bar and click Find:将以下过滤器复制到Compass查询栏中，然后单击“查找”：

{ status: "A", $or: [ { qty: { $lt: 30 } }, { item: /^p/ } ] }

cursor = db.inventory.find({
    "status": "A",
    "$or": [{"qty": {"$lt": 30}}, {"item": {"$regex": "^p"}}]})

findIterable = collection.find(
        and(eq("status", "A"),
                or(lt("qty", 30), regex("item", "^p")))
);

const cursor = db.collection('inventory').find({
  status: 'A',
  $or: [{ qty: { $lt: 30 } }, { item: { $regex: '^p' } }]
});

$cursor = $db->inventory->find([
    'status' => 'A',
    '$or' => [
        ['qty' => ['$lt' => 30]],
        // Alternatively: ['item' => new \MongoDB\BSON\Regex('^p')]
        ['item' => ['$regex' => '^p']],
    ],
]);

cursor = db.inventory.find({
    "status": "A",
    "$or": [{"qty": {"$lt": 30}}, {"item": {"$regex": "^p"}}]})

findPublisher = collection.find(
        and(eq("status", "A"),
                or(lt("qty", 30), regex("item", "^p")))
);

var builder = Builders<BsonDocument>.Filter;
var filter = builder.And(
    builder.Eq("status", "A"),
    builder.Or(builder.Lt("qty", 30), builder.Regex("item", new BsonRegularExpression("^p"))));
var result = collection.Find(filter).ToList();

$cursor = $db->coll("inventory")->find(
    {
        status => "A",
        '$or'  => [ { qty => { '$lt' => 30 } }, { item => { '$regex' => "^p" } } ]
    }
);

client[:inventory].find(status: 'A',
                        '$or' => [{ qty: { '$lt' => 30 } },
                                  { item: { '$regex' => BSON::Regexp::Raw.new('^p') } }
                        ])

findObservable = collection.find(and(
  equal("status", "A"),
  or(lt("qty", 30), regex("item", "^p")))
)

cursor, err := coll.Find(
	context.Background(),
	bson.D{
		{"status", "A"},
		{"$or", bson.A{
			bson.D{{"qty", bson.D{{"$lt", 30}}}},
			bson.D{{"item", primitive.Regex{Pattern: "^p", Options: ""}}},
		}},
	})

The operation corresponds to the following SQL statement:该操作对应于以下SQL语句：

SELECT * FROM inventory WHERE status = "A" AND ( qty < 30 OR item LIKE "p%")

Note

MongoDB supports regular expressions $regex queries to perform string pattern matches.MongoDB支持正则表达式$regex查询来执行字符串模式匹配。

Additional Query Tutorials附加查询教程¶

For additional query examples, see:有关其他查询示例，请参阅：

• Query on Embedded/Nested Documents对嵌入/嵌套文档的查询
• Query an Array查询数组
• Query an Array of Embedded Documents查询嵌入文档的数组
• Project Fields to Return from Query要从查询返回的项目字段
• Query for Null or Missing Fields查询空字段或缺少字段

Behavior行为¶