通配符
定义
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 |
---|---|---|---|---|
| 字符串或字符串数组 | 要搜索的一个或多个字符串。 | 是 | |
| 字符串或字符串数组 | 是 | ||
| 布尔 | 如果针对分析字段运行查询,则必须设置为 | no |
|
| 对象 | 修改分配给匹配搜索词结果的分数。选项包括:
有关在查询中使用 | 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。
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*" } } }, { "$project": { "_id": 0, "title": 1 } } ])
在 movies
集合的 Aggregations 标签页中,从下拉菜单中选择阶段并为该阶段添加查询,以配置以下每个管道阶段。单击 Add Stage 添加其他阶段。
管道阶段 | 查询 | ||||||
---|---|---|---|---|---|---|---|
|
| ||||||
|
|
using MongoDB.Bson; using MongoDB.Bson.Serialization.Attributes; using MongoDB.Bson.Serialization.Conventions; using MongoDB.Driver; using MongoDB.Driver.Search; public class WildcardSingleCharacter { private const string MongoConnectionString = "<connection-string>"; public static void Main(string[] args) { // allow automapping of the camelCase database fields to our MovieDocument var camelCaseConvention = new ConventionPack { new CamelCaseElementNameConvention() }; ConventionRegistry.Register("CamelCase", camelCaseConvention, type => true); // connect to your Atlas cluster var mongoClient = new MongoClient(MongoConnectionString); var mflixDatabase = mongoClient.GetDatabase("sample_mflix"); var moviesCollection = mflixDatabase.GetCollection<MovieDocument>("movies"); // define and run pipeline var results = moviesCollection.Aggregate() .Search(Builders<MovieDocument>.Search.Wildcard(movie => movie.Title, "Green D*")) .Project<MovieDocument>(Builders<MovieDocument>.Projection .Include(movie => movie.Title) .Exclude(movie => movie.Id)) .ToList(); // print results foreach (var movie in results) { Console.WriteLine(movie.ToJson()); } } } [ ]public class MovieDocument { [ ] public ObjectId Id { get; set; } public string Title { get; set; } }
package main import ( "context" "fmt" "go.mongodb.org/mongo-driver/bson" "go.mongodb.org/mongo-driver/mongo" "go.mongodb.org/mongo-driver/mongo/options" ) func main() { // connect to your Atlas cluster client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("<connection-string>")) if err != nil { panic(err) } defer client.Disconnect(context.TODO()) // set namespace collection := client.Database("sample_mflix").Collection("movies") // define pipeline stages searchStage := bson.D{{"$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 | ||||||
---|---|---|---|---|---|---|---|
|
| ||||||
|
| ||||||
|
|
$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()); } } } [ ]public class MovieDocument { [ ] 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。
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 | ||||||
---|---|---|---|---|---|---|---|
|
| ||||||
|
| ||||||
|
|
$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()); } } } [ ]public class MovieDocument { [ ] 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?'}