通配符

在此页面上

定义

语法
选项
行为
示例

定义

wildcard

wildcard 操作符在搜索字符串中使用可匹配任何字符的特殊字符进行查询。

字符	说明
`?`	匹配任意单个字符。
`*`	匹配 0 个或更多字符。
`\`	转义字符。

wildcard 为词级操作符，因而不会分析 query 字段。术语级操作符非常适合关键字分析器，因为 query 字段被视为包含特殊字符的单个术语。有关根据已分析的 query 字段与未分析的 query 字段进行查询的示例，请参阅已分析字段示例。

语法

wildcard 通过以下语法实现：

{
  $search: {
    "index": <index name>, // optional, defaults to "default"
    "wildcard": {
      "query": "<search-string>",
      "path": "<field-to-search>",
      "allowAnalyzedField": <boolean>,
      "score": <options>
    }
  }
}

选项

wildcard 使用以下词条来构造查询：

字段	类型	说明	必要性	默认
`query`	字符串或字符串数组	要搜索的一个或多个字符串。	是
`path`	字符串或字符串数组	要搜索的一个或多个带索引字段。还可以指定通配符路径进行搜索。有关更多信息，请参阅路径构造。	是
`allowAnalyzedField`	布尔	如果针对分析字段运行查询，则必须设置为 `true`。	no	`false`
`score`	对象	修改分配给匹配搜索词结果的分数。选项包括： `boost`将生成的分数乘以给定数字。 `constant`将结果分数替换为给定数字。 `function`：使用给定的表达式替换结果分数。有关在查询中使用 `score` 的信息，请参阅对结果中的文档进行评分。	no

行为

wildcard 是术语级操作符，这意味着不分析 query 字段。通过将 allowAnalyzedField 选项设置为 true，可以使用 wildcard 操作符对索引期间分析的字段执行搜索，但结果将反映未对查询文本进行分析。

例子

假设使用标准分析器对字段 foo bar baz 进行了索引。Atlas Search 对该字段进行分析并索引为 foo 、bar 和 baz 。在此字段中搜索 foo bar* 找不到任何结果，因为通配符操作符将 foo bar* 视为结尾带有通配符的单个搜索词。换句话说，Atlas Search 在字段中搜索以 foo bar 开头的任何词，但找不到任何结果，因为不存在这样的词。

例子

在使用 keyword 分析器进行索引的字段上搜索*Star Trek*，即可查找该字段在任何上下文中包含字符串 Star Trek 的所有文档。在使用标准分析器进行索引的字段上搜索 *Star Trek* 找不到任何结果，因为 Star 和 Trek 之间有空格，而索引并不包含空格。

转义字符行为

在 mongosh 中或驱动程序中使用转义字符时，必须在要转义的字符前使用双反斜杠。

例子

要创建一个通配符表达式来搜索聚合管道中包含字面星号的任何字符串，请使用以下表达式：

"*\\**"

第一个和最后一个星号作为通配符，可匹配任何字符，而 \\* 则匹配文字星号。

注意

使用以下表达式对文本反斜杠进行转义：

"*\\\*"

➤ 使用 Select your language（选择您的语言）下拉菜单设置此页面上示例的语言。

示例

以下示例将 sample_mflix 数据库的 movies 集合与使用关键字分析器的自定义索引定义结合使用。如果集群有示例数据集，则可以在 movies 集合上创建 Atlas Search 索引，并在集群上运行示例查询。

提示

如果您已经加载示例数据集，请按照 Atlas Search 入门教程，创建索引定义并运行 Atlas Search 查询。

在 Search Tester 中查看和编辑查询语法：

AtlasGoClusters在Atlas中，Go项目的页面。

如果尚未显示，请从导航栏上的 Organizations 菜单中选择包含所需项目的组织。
如果尚未显示，请从导航栏的Projects菜单中选择所需的项目。
如果尚未出现，请单击侧边栏中的 Clusters（集群）。
会显示集群页面。

转到集群的 Atlas Search 页面。

您可以从侧边栏、 Data Explorer 或集群详细信息页面转到 Atlas Search 页面。

在侧边栏中，单击 Services 标题下的 Atlas Search。
从 Select data source 下拉菜单中选择您的集群并单击 Go to Atlas Search。
将显示 Atlas Search 页面。

单击集群的对应 Browse Collections 按钮。
展开数据库并选择集合。
单击该集合的 Search Indexes 标签页。
将显示 Atlas Search 页面。

单击集群的名称。
单击 Atlas Search 标签页。
将显示 Atlas Search 页面。

查看和编辑查询语法。

单击要查询的索引右侧的 Query 按钮。
单击Edit Query查看 JSON格式的默认查询语法示例。

在 mongosh 提示符处运行以下命令以使用 sample_mflix 数据库：

use sample_mflix

索引定义

以下索引定义使用关键字分析器对 movies 集合中的 title 字段进行索引：

1 {
2   "mappings": {
3     "fields": {
4       "title": {
5         "analyzer": "lucene.keyword",
6         "type": "string"
7       }
8     }
9   }
10 }

以下示例在所有 title 字段中搜索以 Green D 开头、后跟任意数量的其他字符的电影标题。

将以下查询复制并粘贴到 Query Editor 中，然后点击 Query Editor 中的 Search 按钮。

[
  {
    $search: {
      "wildcard": {
        "path": "title",
        "query": "Green D*"
      }
    }
  }
]

db.movies.aggregate([
  {
    "$search": {
      "wildcard": {
        "path": "title",
        "query": "Green D*"
      }
    }
  },
  {
    "$project": {
      "_id": 0,
      "title": 1
    }
  }
])

在 movies 集合的 Aggregations 标签页中，从下拉菜单中选择阶段并为该阶段添加查询，以配置以下每个管道阶段。单击 Add Stage 添加其他阶段。

管道阶段

查询

$search

{
  "wildcard": {
    "query": "Green D*",
    "path": "title"
  }
}

$project

{
  "_id": 0,
  "title": 1,
}

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Bson.Serialization.Conventions;
using MongoDB.Driver;
using MongoDB.Driver.Search;
public class WildcardSingleCharacter
{
    private const string MongoConnectionString = "<connection-string>";
    public static void Main(string[] args)
    {
        // allow automapping of the camelCase database fields to our MovieDocument
        var camelCaseConvention = new ConventionPack { new CamelCaseElementNameConvention() };
        ConventionRegistry.Register("CamelCase", camelCaseConvention, type => true);
        // connect to your Atlas cluster
        var mongoClient = new MongoClient(MongoConnectionString);
        var mflixDatabase = mongoClient.GetDatabase("sample_mflix");
        var moviesCollection = mflixDatabase.GetCollection<MovieDocument>("movies");
        // define and run pipeline
        var results = moviesCollection.Aggregate()
            .Search(Builders<MovieDocument>.Search.Wildcard(movie => movie.Title, "Green D*"))
            .Project<MovieDocument>(Builders<MovieDocument>.Projection
                .Include(movie => movie.Title)
                .Exclude(movie => movie.Id))
            .ToList();
        // print results
        foreach (var movie in results)
        {
            Console.WriteLine(movie.ToJson());
        }
    }
}
[BsonIgnoreExtraElements]
public class MovieDocument
{
    [BsonIgnoreIfDefault]
    public ObjectId Id { get; set; }
    public string Title { get; set; }
}

package main
import (
	"context"
	"fmt"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
	// connect to your Atlas cluster
	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("<connection-string>"))
	if err != nil {
		panic(err)
	}
	defer client.Disconnect(context.TODO())
	// set namespace
	collection := client.Database("sample_mflix").Collection("movies")
	// define pipeline stages
	searchStage := bson.D{{"$search", bson.D{{"wildcard", bson.D{{"path", "title"}, {"query", "Green D*"}}}}}}
	projectStage := bson.D{{"$project", bson.D{{"title", 1}, {"_id", 0}}}}
	// run pipeline
	cursor, err := collection.Aggregate(context.TODO(), mongo.Pipeline{searchStage, projectStage})
	if err != nil {
		panic(err)
	}
	// print results
	var results []bson.D
	if err = cursor.All(context.TODO(), &results); err != nil {
		panic(err)
	}
	for _, result := range results {
		fmt.Println(result)
	}
}

import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Aggregates.project;
import static com.mongodb.client.model.Projections.excludeId;
import static com.mongodb.client.model.Projections.fields;
import static com.mongodb.client.model.Projections.include;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import java.util.Arrays;
public class WildcardSingleCharacter {
    public static void main(String[] args) {
        // connect to your Atlas cluster
        String uri = "<connection-string>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            // set namespace
            MongoDatabase database = mongoClient.getDatabase("sample_mflix");
            MongoCollection<Document> collection = database.getCollection("movies");
            
            // define pipeline
            Document agg = new Document("query", "Green D*").append("path", "title");
            // run pipeline and print results
            collection.aggregate(Arrays.asList(
                eq("$search", eq("wildcard", agg)),
                project(fields(excludeId(), include("title"))))).forEach(doc -> System.out.println(doc.toJson()));
        }
    }
}

import com.mongodb.client.model.Aggregates.project
import com.mongodb.client.model.Filters.eq
import com.mongodb.client.model.Projections.*
import com.mongodb.kotlin.client.coroutine.MongoClient
import kotlinx.coroutines.runBlocking
import org.bson.Document
fun main() {
    val uri = "<connection-string>"
    val mongoClient = MongoClient.create(uri)
    val database = mongoClient.getDatabase("sample_mflix")
    val collection = database.getCollection<Document>("movies")
    runBlocking {
        val agg = Document("query", "Green D*").append("path", "title")
        val resultsFlow = collection.aggregate<Document>(
            listOf(
                eq("\$search", eq("wildcard", agg)),
                project(fields(
                    excludeId(),
                    include("title")
                ))
            )
        )
        resultsFlow.collect { println(it) }
    }
    mongoClient.close()
}

const { MongoClient } = require("mongodb");
// connect to your Atlas cluster
const uri =
    "<connection-string>";
const client = new MongoClient(uri);
async function run() {
    try {
        await client.connect();
        // set namespace
        const database = client.db("sample_mflix");
        const coll = database.collection("movies");
        // define pipeline
        const agg = [
            {$search: {wildcard: {query: "Green D*", path: "title"}}},
            {$project: {_id: 0, title: 1}},
        ];
        // run pipeline
        const result = await coll.aggregate(agg);
        // print results
        await result.forEach((doc) => console.log(doc));
    } finally {
        await client.close();
    }
}
run().catch(console.dir);

import pymongo
# connect to your Atlas cluster
client = pymongo.MongoClient('<connection-string>')
# define pipeline
pipeline = [
    {"$search": {"wildcard": {"query": "Green D*", "path": "title"}}},
    {"$project": {"_id": 0, "title": 1}},
]
# run pipeline
result = client["sample_mflix"]["movies"].aggregate(pipeline)
# print results
for i in result:
    print(i)

以上查询返回以下结果：

SCORE: 1  _id:  "573a1393f29313caabcddaf5"
  plot: "Sophie loved Edmund, but he left town when her parents forced her to m…"
  genres: Array
  runtime: 141
SCORE: 1  _id:  "573a13a2f29313caabd0a4e4"
  plot: "The story of some Vietnamese refugees as they first arrive at Camp Pen…"
  genres: Array
  runtime: 115

Search Tester 可能不会显示其所返回文档的所有字段。要查看所有字段，包括在查询路径中指定的字段，请展开结果中的文档。

{ "title" : "Green Dolphin Street" }
{ "title" : "Green Dragon" }

{ "title" : "Green Dolphin Street" }
{ "title" : "Green Dragon" }

{ "title" : "Green Dolphin Street" }
{ "title" : "Green Dragon" }

[{title Green Dolphin Street}]
[{title Green Dragon}]

{"title": "Green Dolphin Street"}
{"title": "Green Dragon"}

Document{{title=Green Dolphin Street}}
Document{{title=Green Dragon}}

{ title: 'Green Dolphin Street' }
{ title: 'Green Dragon' }

{'title': 'Green Dolphin Street'}
{'title': 'Green Dragon'}

以下示例在所有 title 字段中搜索以字符串 Wom?n（其中 ? 可以是任意单个字符）开头的电影标题，然后是空格，然后是任意数量的其他字符。

将以下查询复制并粘贴到 Query Editor 中，然后点击 Query Editor 中的 Search 按钮。

[
  {
    $search: {
      "wildcard": {
        "path": "title",
        "query": "Wom?n *"
      }
    }
  }
]

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

db.movies.aggregate([
  {
    "$search": {
      "wildcard": {
        "path": "title",
        "query": "Wom?n *"
      }
    }
  },
  {
    "$limit": 5
  },
  {
    "$project": {
      "_id": 0,
      "title": 1
    }
  }
])

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

在 movies 集合的 Aggregations 标签页中，从下拉菜单中选择阶段并为该阶段添加查询，以配置以下每个管道阶段。单击 Add Stage 添加其他阶段。

管道阶段

查询

$search

{
  "wildcard": {
    "query": "Wom?n *",
    "path": "title"
  }
}

$limit

$project

{
  "_id": 0,
  "title": 1,
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Bson.Serialization.Conventions;
using MongoDB.Driver;
using MongoDB.Driver.Search;
public class WildcardMultipleCharacter
{
    private const string MongoConnectionString = "<connection-string>";
    public static void Main(string[] args)
    {
        // allow automapping of the camelCase database fields to our MovieDocument
        var camelCaseConvention = new ConventionPack { new CamelCaseElementNameConvention() };
        ConventionRegistry.Register("CamelCase", camelCaseConvention, type => true);
        // connect to your Atlas cluster
        var mongoClient = new MongoClient(MongoConnectionString);
        var mflixDatabase = mongoClient.GetDatabase("sample_mflix");
        var moviesCollection = mflixDatabase.GetCollection<MovieDocument>("movies");
        // define and run pipeline
        var results = moviesCollection.Aggregate()
            .Search(Builders<MovieDocument>.Search.Wildcard(movie => movie.Title, "Wom?n *"))
            .Project<MovieDocument>(Builders<MovieDocument>.Projection
                .Include(movie => movie.Title)
                .Exclude(movie => movie.Id))
            .Limit(5)
            .ToList();
        // print results
        foreach (var movie in results)
        {
            Console.WriteLine(movie.ToJson());
        }
    }
}
[BsonIgnoreExtraElements]
public class MovieDocument
{
    [BsonIgnoreIfDefault]
    public ObjectId Id { get; set; }
    public string Title { get; set; }
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

package main
import (
	"context"
	"fmt"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
	// connect to your Atlas cluster
	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("<connection-string>"))
	if err != nil {
		panic(err)
	}
	defer client.Disconnect(context.TODO())
	// set namespace
	collection := client.Database("sample_mflix").Collection("movies")
	// define pipeline stages
	searchStage := bson.D{{"$search", bson.D{{"wildcard", bson.D{{"path", "title"}, {"query", "Wom?n *"}}}}}}
	limitStage := bson.D{{"$limit", 5}}
	projectStage := bson.D{{"$project", bson.D{{"title", 1}, {"_id", 0}}}}
	// run pipeline
	cursor, err := collection.Aggregate(context.TODO(), mongo.Pipeline{searchStage, limitStage, projectStage})
	if err != nil {
		panic(err)
	}
	// print results
	var results []bson.D
	if err = cursor.All(context.TODO(), &results); err != nil {
		panic(err)
	}
	for _, result := range results {
		fmt.Println(result)
	}
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Aggregates.limit;
import static com.mongodb.client.model.Aggregates.project;
import static com.mongodb.client.model.Projections.excludeId;
import static com.mongodb.client.model.Projections.fields;
import static com.mongodb.client.model.Projections.include;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import java.util.Arrays;
public class WildcardMultiCharacter {
    public static void main(String[] args) {
        // connect to your Atlas cluster
        String uri = "<connection-string>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            // set namespsace
            MongoDatabase database = mongoClient.getDatabase("sample_mflix");
            MongoCollection<Document> collection = database.getCollection("movies");
            // define pipeline
            Document agg = new Document("query", "Wom?n *").append("path", "title");
            // run pipeline and print results
            collection.aggregate(Arrays.asList(
                eq("$search", eq("wildcard", agg)),
                limit(5),
                project(fields(excludeId(), include("title"))))).forEach(doc -> System.out.println(doc.toJson()));
        }
    }
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import com.mongodb.client.model.Aggregates.limit
import com.mongodb.client.model.Aggregates.project
import com.mongodb.client.model.Filters.eq
import com.mongodb.client.model.Projections.*
import com.mongodb.kotlin.client.coroutine.MongoClient
import kotlinx.coroutines.runBlocking
import org.bson.Document
fun main() {
    val uri = "<connection-string>"
    val mongoClient = MongoClient.create(uri)
    val database = mongoClient.getDatabase("sample_mflix")
    val collection = database.getCollection<Document>("movies")
    runBlocking {
        val agg = Document("query", "Wom?n *").append("path", "title")
        val resultsFlow = collection.aggregate<Document>(
            listOf(
                eq("\$search", eq("wildcard", agg)),
                limit(5),
                project(fields(
                    excludeId(),
                    include("title")
                ))
            )
        )
        resultsFlow.collect { println(it) }
    }
    mongoClient.close()
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

const { MongoClient } = require("mongodb");
// connect to your Atlas cluster
const uri =
    "<connection-string>";
const client = new MongoClient(uri);
async function run() {
    try {
        await client.connect();
        // set namespace
        const database = client.db("sample_mflix");
        const coll = database.collection("movies");
        // define pipeline
        const agg = [
            {$search: {wildcard: {query: "Wom?n *", path: "title"}}},
            {$limit: 5},
            {$project: {_id: 0,title: 1}}
        ];
        // run pipeline
        const result = await coll.aggregate(agg);
        // print results
        await result.forEach((doc) => console.log(doc));
    } finally {
        await client.close();
    }
}
run().catch(console.dir);

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import pymongo
# connect to your Atlas cluster
client = pymongo.MongoClient('<connection-string>')
# define pipeline
pipeline = [
    {"$search": {"wildcard": {"query": "Wom?n *", "path": "title"}}},
    {"$limit": 5},
    {"$project": {"_id": 0, "title": 1}},
]
# run pipeline
result = client["sample_mflix"]["movies"].aggregate(pipeline)
# print results
for i in result:
    print(i)

以上查询返回以下结果：

SCORE: 1  _id:  "573a1393f29313caabcdcbdd"
  plot: "Rival reporters Sam and Tess fall in love and get married, only to fin…"
  genres: Array
  runtime: 114
SCORE: 1  _id:  "573a1394f29313caabce08c6"
  plot: "A married, middle-aged woman is shocked to discover that her husband, …"
  genres: Array
  runtime: 93
SCORE: 1  _id:  "573a1395f29313caabce254c"
  plot: "An entomologist searching for insects by the seaside is trapped by loc…"
  genres: Array
  runtime: 123
SCORE: 1  _id:  "573a1396f29313caabce42e5"
  plot: "The battle of the sexes and relationships among the elite of Britian's…"
  genres: Array
  runtime: 131
SCORE: 1  _id:  "573a1398f29313caabceb06d"
  fullplot: "A woman's lover leaves her, and she tries to contact him to find out w…"
  imdb: Object
  year: 1988
SCORE: 1  _id:  "573a139df29313caabcf9c83"
  plot: "A new woman comes between a widower and his adult son."
  genres: Array
  runtime: 110
SCORE: 1  _id:  "573a13a0f29313caabd050bf"
  fullplot: "Isabella is a great cook, making her husband's restaurant in Bahia, Br…"
  imdb: Object
  year: 2000
SCORE: 1  _id:  "573a13aaf29313caabd22c05"
  countries: Array
  genres: Array
  runtime: 115
SCORE: 1  _id:  "573a13aef29313caabd2d899"
  countries: Array
  genres: Array
  runtime: 72
SCORE: 1  _id:  "573a13aff29313caabd32566"
  fullplot: "An adaptation of Bishop T.D. Jakes' self-help novel, chronciling a wom…"
  imdb: Object
  year: 2004

Search Tester 可能不会显示其所返回文档的所有字段。要查看所有字段，包括在查询路径中指定的字段，请展开结果中的文档。

{ "title" : "Woman of the Year" }
{ "title" : "Woman in a Dressing Gown" }
{ "title" : "Woman in the Dunes" }
{ "title" : "Women in Love" }
{ "title" : "Women on the Verge of a Nervous Breakdown" }

{ "title" : "Woman of the Year" }
{ "title" : "Woman in a Dressing Gown" }
{ "title" : "Woman in the Dunes" }
{ "title" : "Women in Love" }
{ "title" : "Women on the Verge of a Nervous Breakdown" }

{ "title" : "Woman of the Year" }
{ "title" : "Woman in a Dressing Gown" }
{ "title" : "Woman in the Dunes" }
{ "title" : "Women in Love" }
{ "title" : "Women on the Verge of a Nervous Breakdown" }

[{title Woman of the Year}]
[{title Woman in a Dressing Gown}]
[{title Woman in the Dunes}]
[{title Women in Love}]
[{title Women on the Verge of a Nervous Breakdown}]

{"title": "Woman of the Year"}
{"title": "Woman in a Dressing Gown"}
{"title": "Woman in the Dunes"}
{"title": "Women in Love"}
{"title": "Women on the Verge of a Nervous Breakdown"}

Document{{title=Woman in the Meadow}}
Document{{title=Woman on the Beach}}
Document{{title=Woman in Love}}
Document{{title=Woman of the Year}}
Document{{title=Woman in a Dressing Gown}}

{ title: 'Woman of the Year' }
{ title: 'Woman in a Dressing Gown' }
{ title: 'Woman in the Dunes' }
{ title: 'Women in Love' }
{ title: 'Women on the Verge of a Nervous Breakdown' }

{'title': 'Woman of the Year'}
{'title': 'Woman in a Dressing Gown'}
{'title': 'Woman in the Dunes'}
{'title': 'Women in Love'}
{'title': 'Women on the Verge of a Nervous Breakdown'}

转义字符示例

下面的示例搜索其中 title 字段以问号结尾的文档。

注意

以下示例将在 mongosh 中运行。有关在驱动程序中使用转义字符的更多信息，请参阅转义字符行为。

query 字段中的 * 字符与任何字符匹配，而 \\? 字符串与文字问号匹配。

将以下查询复制并粘贴到 Query Editor 中，然后点击 Query Editor 中的 Search 按钮。

[
  {
    $search: {
      "wildcard": {
        "path": "title",
        "query": "*\\?"
      }
    }
  }
]

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

db.movies.aggregate([
  {
    "$search": {
      "wildcard": {
        "path": "title",
        "query": "*\\?"
      }
    }
  },
  {
    "$limit": 5
  },
  {
    "$project": {
      "_id": 0,
      "title": 1
    }
  }
])

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

在 movies 集合的 Aggregations 标签页中，从下拉菜单中选择阶段并为该阶段添加查询，以配置以下每个管道阶段。单击 Add Stage 添加其他阶段。

管道阶段

查询

$search

{
  "wildcard": {
    "query": "*\\?",
    "path": "title"
  }
}

$limit

$project

{
  "_id": 0,
  "title": 1,
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Bson.Serialization.Conventions;
using MongoDB.Driver;
using MongoDB.Driver.Search;
public class WildcardEscapeCharacter
{
    private const string MongoConnectionString = "<connection-string>";
    public static void Main(string[] args)
    {
        // allow automapping of the camelCase database fields to our MovieDocument
        var camelCaseConvention = new ConventionPack { new CamelCaseElementNameConvention() };
        ConventionRegistry.Register("CamelCase", camelCaseConvention, type => true);
        // connect to your Atlas cluster
        var mongoClient = new MongoClient(MongoConnectionString);
        var mflixDatabase = mongoClient.GetDatabase("sample_mflix");
        var moviesCollection = mflixDatabase.GetCollection<MovieDocument>("movies");
        // define and run pipeline
        var results = moviesCollection.Aggregate()
            .Search(Builders<MovieDocument>.Search.Wildcard(movie => movie.Title, "*\\?"))
            .Project<MovieDocument>(Builders<MovieDocument>.Projection
                .Include(movie => movie.Title)
                .Exclude(movie => movie.Id))
            .Limit(5)
            .ToList();
        // print results
        foreach (var movie in results)
        {
            Console.WriteLine(movie.ToJson());
        }
    }
}
[BsonIgnoreExtraElements]
public class MovieDocument
{
    [BsonIgnoreIfDefault]
    public ObjectId Id { get; set; }
    public string Title { get; set; }
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

package main
import (
	"context"
	"fmt"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
	// connect to your Atlas cluster
	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("<connection-string>"))
	if err != nil {
		panic(err)
	}
	defer client.Disconnect(context.TODO())
	// set namespace
	collection := client.Database("sample_mflix").Collection("movies")
	// define pipeline stages
	searchStage := bson.D{{"$search", bson.D{{"wildcard", bson.D{{"path", "title"}, {"query", "*\\?"}}}}}}
	limitStage := bson.D{{"$limit", 5}}
	projectStage := bson.D{{"$project", bson.D{{"title", 1}, {"_id", 0}}}}
	// run pipeline
	cursor, err := collection.Aggregate(context.TODO(), mongo.Pipeline{searchStage, limitStage, projectStage})
	if err != nil {
		panic(err)
	}
	// print results
	var results []bson.D
	if err = cursor.All(context.TODO(), &results); err != nil {
		panic(err)
	}
	for _, result := range results {
		fmt.Println(result)
	}
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Aggregates.limit;
import static com.mongodb.client.model.Aggregates.project;
import static com.mongodb.client.model.Projections.excludeId;
import static com.mongodb.client.model.Projections.fields;
import static com.mongodb.client.model.Projections.include;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import java.util.Arrays;
public class WildcardEscapeCharacter {
    public static void main(String[] args) {
        // connect to your Atlas cluster
        String uri = "<connection-string>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            // set namespace
            MongoDatabase database = mongoClient.getDatabase("sample_mflix");
            MongoCollection<Document> collection = database.getCollection("movies");
            
            // define pipeline
            Document agg = new Document("query", "*\\?").append("path", "title");
            // run pipeline and print results
            collection.aggregate(Arrays.asList(
                eq("$search", eq("wildcard", agg)),
                limit(5),
                project(fields(excludeId(), include("title"))))).forEach(doc -> System.out.println(doc.toJson()));
        }
    }
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import com.mongodb.client.model.Aggregates.limit
import com.mongodb.client.model.Aggregates.project
import com.mongodb.client.model.Filters.eq
import com.mongodb.client.model.Projections.*
import com.mongodb.kotlin.client.coroutine.MongoClient
import kotlinx.coroutines.runBlocking
import org.bson.Document
fun main() {
    val uri = "<connection-string>"
    val mongoClient = MongoClient.create(uri)
    val database = mongoClient.getDatabase("sample_mflix")
    val collection = database.getCollection<Document>("movies")
    runBlocking {
        val agg = Document("query", "*\\?").append("path", "title")
        val resultsFlow = collection.aggregate<Document>(
            listOf(
                eq("\$search", eq("wildcard", agg)),
                limit(5),
                project(fields(
                    excludeId(),
                    include("title")
                ))
            )
        )
        resultsFlow.collect { println(it) }
    }
    mongoClient.close()
}

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

const { MongoClient } = require("mongodb");
// connect to your Atlas cluster
const uri =
    "<connection-string>";
const client = new MongoClient(uri);
async function run() {
    try {
        await client.connect();
        // set namespace
        const database = client.db("sample_mflix");
        const coll = database.collection("movies");
        // define pipeline
        const agg = [
            {$search: {wildcard: {query: "*\\?", path: "title"}}},
            {$limit: 5},
            {$project: {_id: 0,title: 1}}
        ];
        // run pipeline
        const result = await coll.aggregate(agg);
        // print results
        await result.forEach((doc) => console.log(doc));
    } finally {
        await client.close();
    }
}
run().catch(console.dir);

$limit 阶段将结果限制为 5 个文档，而 $project 阶段将结果限制为仅 title 字段。

import pymongo
# connect to your Atlas cluster
client = pymongo.MongoClient('<connection-string>')
# define pipeline
pipeline = [
    {"$search": {"wildcard": {"query": "*\\?", "path": "title"}}},
    {"$limit": 5},
    {"$project": {"_id": 0, "title": 1}},
]
# run pipeline
result = client["sample_mflix"]["movies"].aggregate(pipeline)
# print results
for i in result:
    print(i)

以上查询返回以下结果：

SCORE: 1  _id:  "573a1390f29313caabcd5ea4"
  plot: "A District Attorney's outspoken stand on abortion gets him in trouble …"
  genres: Array
  runtime: 62
SCORE: 1  _id:  "573a1392f29313caabcdab4a"
  plot: "Robin is crooning to a Mae West-like Jenny Wren when he is shot with a…"
  genres: Array
  runtime: 8
SCORE: 1  _id:  "573a1394f29313caabce08ab"
  plot: "Elmer Fudd is again hunting rabbits - only this time it's an opera. Wa…"
  genres: Array
  runtime: 7
SCORE: 1  _id:  "573a1394f29313caabce08c8"
  plot: "To save his career, an ad man wants a sex symbol to endorse a lipstick…"
  genres: Array
  runtime: 93
SCORE: 1  _id:  "573a1395f29313caabce1555"
  plot: "In order to get back into the good graces with his wife with whom he h…"
  genres: Array
  runtime: 115
SCORE: 1  _id:  "573a1395f29313caabce1dce"
  plot: "A former child star torments her crippled sister in a decaying Hollywo…"
  genres: Array
  runtime: 134
SCORE: 1  _id:  "573a1395f29313caabce2422"
  plot: "Roger Willoughby is considered to be a leading expert on sports fishin…"
  genres: Array
  runtime: 120
SCORE: 1  _id:  "573a1395f29313caabce2d63"
  plot: "The true story of the departure of the German occupiers from Paris in …"
  genres: Array
  runtime: 173
SCORE: 1  _id:   "573a1395f29313caabce2db5"
  plot: "In this excoriating satire of the fashion industry, Polly Maggoo is a …"
  genres: Array
  runtime: 101
SCORE: 1  _id:   "573a1395f29313caabce2ecc"
  plot: "A bitter aging couple with the help of alcohol, use a young couple to …"
  genres: Array
  runtime: 131

Search Tester 可能不会显示其所返回文档的所有字段。要查看所有字段，包括在查询路径中指定的字段，请展开结果中的文档。

{ "title" : "Where Are My Children?" }
{ "title" : "Who Killed Cock Robin?" }
{ "title" : "What's Opera, Doc?" }
{ "title" : "Will Success Spoil Rock Hunter?" }
{ "title" : "Who Was That Lady?" }

{ "title" : "Where Are My Children?" }
{ "title" : "Who Killed Cock Robin?" }
{ "title" : "What's Opera, Doc?" }
{ "title" : "Will Success Spoil Rock Hunter?" }
{ "title" : "Who Was That Lady?" }

{ "title" : "Where Are My Children?" }
{ "title" : "Who Killed Cock Robin?" }
{ "title" : "What's Opera, Doc?" }
{ "title" : "Will Success Spoil Rock Hunter?" }
{ "title" : "Who Was That Lady?" }

[{title Where Are My Children?}]
[{title Who Killed Cock Robin?}]
[{title What's Opera, Doc?}]
[{title Will Success Spoil Rock Hunter?}]
[{title Who Was That Lady?}]

{"title": "Where Are My Children?"}
{"title": "Who Killed Cock Robin?"}
{"title": "What's Opera, Doc?"}
{"title": "Will Success Spoil Rock Hunter?"}
{"title": "Who Was That Lady?"}

Document{{title=Who Are You, Polly Magoo?}}
Document{{title=Where Were You When the Lights Went Out?}}
Document{{title=Why Does Herr R. Run Amok?}}
Document{{title=What's Up, Doc?}}
Document{{title=Who Is Killing the Great Chefs of Europe?}}

{ title: 'Where Are My Children?' }
{ title: 'Who Killed Cock Robin?' }
{ title: "What's Opera, Doc?" }
{ title: 'Will Success Spoil Rock Hunter?' }
{ title: 'Who Was That Lady?' }

{'title': 'Where Are My Children?'}
{'title': 'Who Killed Cock Robin?'}
{'title': "What's Opera, Doc?"}
{'title': 'Will Success Spoil Rock Hunter?'}
{'title': 'Who Was That Lady?'}

后退

text

来年

3. 构造查询路径

1	{
2	"mappings": {
3	"fields": {
4	"title": {
5	"analyzer": "lucene.keyword",
6	"type": "string"
7	}
8	}
9	}
10	}

定义

语法

选项

行为

例子

例子

转义字符行为

例子

注意

示例

提示

AtlasGoClusters在Atlas中，Go项目的 页面。

转到集群的 Atlas Search 页面。

查看和编辑查询语法。

索引定义

转义字符示例

注意

AtlasGoClusters在Atlas中，Go项目的页面。