text
On this page
Definition
The text
operator performs a full-text search using the analyzer that you specify in the index configuration. If you omit an analyzer, the text
operator
uses the default standard analyzer.
Syntax
text
has the following syntax:
{ $search: { "index": <index name>, // optional, defaults to "default" "text": { "query": "<search-string>", "path": "<field-to-search>", "fuzzy": <options>, "matchCriteria": "any" | "all" "score": <options>, "synonyms": "<synonyms-mapping-name>" } } }
Fields
Field | Type | Description | Necessity |
---|---|---|---|
query | string or array of strings | The string or strings to search for. If there are multiple
terms in a string, Atlas Search also looks for a match for each term
in the string separately. | Required |
path | string or array of strings | The indexed field or fields to search. You can also specify a
wildcard path to search. See path
construction for more information. | Required |
fuzzy | document | Enable fuzzy search. Find strings which are similar to the
search term or terms. You can't use fuzzy with synonyms . | Optional |
fuzzy.maxEdits | integer | Maximum number of single-character edits required to match the
specified search term. Value can be 1 or 2 . The default
value is 2 . Uses Damerau-Levenshtein distance. | Optional |
fuzzy.prefixLength | integer | Number of characters at the beginning of each term in the result
that must exactly match. The default value is 0 . | Optional |
fuzzy.maxExpansions | integer | Maximum number of variations to generate and search for.
This limit applies on a per-token basis. The default value is
50 . | Optional |
matchCriteria | string | Criteria to use to match the terms in the query. Value can be one of the following:
If omitted, defaults to | Optional, Recommended |
score | document | Score assigned to matching search term results. Use one of the following options to modify the score:
When you query values in arrays, Atlas Search doesn't alter the score of the matching results based on the number of values inside the array that matched the query. The score would be the same as a single match regardless of the number of matches inside an array. | Optional |
synonyms | string | Required for running queries using synonyms. Name of the synonym mapping definition in
the index definition. Value can't
be an empty string. You can't use Always use | Optional |
Behavior
For text
queries that use synonyms
without matchCriteria
,
Atlas Search only matches documents which contain an exact match of the query terms
(with or without the expanded synonyms).
This behavior might change in the future and your query results might
also change. To avoid service disruptions, always use matchCriteria
when using synonyms
. Or, use synonyms with the phrase
operator.
For example, suppose equivalent synonym mappings for nyc
and new
york city
. A search for i like nyc
returns the following:
Operator Specification | Default Behavior | "matchCriteria": "any" | "matchCriteria": "all" |
---|---|---|---|
text without synonyms | Matches i OR like OR nyc | Matches i OR like OR nyc | Matches i AND like AND nyc |
text with synonyms | Matches i like nyc OR i like new york city | Matches i OR like OR (nyc OR new york city ) | Matches i AND like AND (nyc OR new york city ) |
The amount of time that Atlas Search takes to execute queries that use synonym mappings depends on the number and size of documents in the synonym source collection. A query that uses a synonym mapping that is based on very few synonym documents might be faster than a query that uses a synonym mapping that is based on many synonym documents.
Examples
The examples in this page use the movies
collection in the
sample_mflix
database. After loading the sample dataset into your cluster, create the Atlas Search
index with dynamic mappings and run the example queries on your
cluster. You must also define a synonyms
mapping collection in the
index as shown in the Index Definition Examples to try the
synonyms examples below.
Basic Example
The following Atlas Search example uses the text
operator to search the
title
field in the movies
collection for the term surfer
.
Example
The following query searches the title
field for the term surfer
.
It includes a $project
stage to:
Exclude all fields except
title
Add a field named
score
db.movies.aggregate([ { $search: { "text": { "path": "title", "query": "surfer" } } }, { $project: { "_id": 0, "title": 1, score: { $meta: "searchScore" } } } ])
{ "title" : "Soul Surfer", "score" : 4.518949508666992 } { "title" : "Little Surfer Girl", "score" : 3.8856077194213867 } { "title" : "Fantastic 4: Rise of the Silver Surfer", "score" : 2.489800453186035 }
Fuzzy Examples
The following queries use the text
operator to search the
title
field in the movies
collection for terms that are within
one character variation of each term in the query
phrase naw
yark
. Atlas Search returns different results depending on whether you use the
default fuzzy
options or define the maxExpansions
, prefixLength
,
or maxEdits
fields.
Click the following tabs for example queries that use default and specified options:
Example
The following query searches the title
field for the
phrase naw yark
. It uses the fuzzy
default options
where:
maxEdits
allows up to two character variation of each term in the given phrase to match the query to a document.maxExpansions
considers up to fifty similar terms for each term innaw yark
to find matches.prefixLength
is disabled.
The query also includes a $limit stage to limit the output to 10 results and a $project stage to:
Exclude all fields except
title
Add a field named
score
db.movies.aggregate([ { $search: { "text": { "path": "title", "query": "naw yark", "fuzzy": {} } } }, { $limit: 10 }, { $project: { "_id": 0, "title": 1, score: { $meta: "searchScore" } } } ])
{ "title" : "New York, New York", "score" : 3.6040148735046387 } { "title" : "New York", "score" : 3.323730945587158 } { "title" : "New York Stories", "score" : 2.8579015731811523 } { "title" : "New York Minute", "score" : 2.8579015731811523 } { "title" : "Synecdoche, New York", "score" : 2.8579015731811523 } { "title" : "New York Doll", "score" : 2.8579015731811523 } { "title" : "Little New York", "score" : 2.8579015731811523 } { "title" : "Escape from New York", "score" : 2.506596088409424 } { "title" : "Naked in New York", "score" : 2.506596088409424 } { "title" : "Autumn in New York", "score" : 2.506596088409424 }
Example
The following query searches the title
field for terms
that are within one character of each term in the string
naw yark
. It uses:
The
maxEdits
field to indicate that only one character variation is allowed for each term to match the query to a document.The
maxExpansions
field to indicate that up to one hundred similar terms fornaw
and one hundred similar terms toyark
must be considered when matching the query to a document.
The query also includes a $limit stage to limit the output to 10 results and a $project stage to:
Exclude all fields except
title
Add a field named
score
db.movies.aggregate([ { $search: { "text": { "path": "title", "query": "naw yark", "fuzzy": { "maxEdits": 1, "maxExpansions": 100, } } } }, { $limit: 10 }, { $project: { "_id": 0, "title": 1, score: { $meta: "searchScore" } } } ])
{ "title" : "New York, New York", "score" : 4.38106107711792 } { "title" : "New York", "score" : 4.040346145629883 } { "title" : "New York Stories", "score" : 3.4740817546844482 } { "title" : "New York Minute", "score" : 3.4740817546844482 } { "title" : "Synecdoche, New York", "score" : 3.4740817546844482 } { "title" : "New York Doll", "score" : 3.4740817546844482 } { "title" : "Little New York", "score" : 3.4740817546844482 } { "title" : "Escape from New York", "score" : 3.047032356262207 } { "title" : "Naked in New York", "score" : 3.047032356262207 } { "title" : "Autumn in New York", "score" : 3.047032356262207 }
Example
The following query searches the title
field for terms
that are within one character of each term in the string
naw yark
. It uses:
The
maxEdits
field to indicate that only one character variation is allowed to match the query to a document.The
prefixLength
field to indicate that the first two characters of each term in the stringnaw yark
may not be changed to match the query to a document.
The query also includes a $limit stage to limit the output to 8 results and a $project stage to:
Exclude all fields except
_id
andtitle
Add a field named
score
db.movies.aggregate([ { $search: { "text": { "path": "title", "query": "naw yark", "fuzzy": { "maxEdits": 1, "prefixLength": 2, } } } }, { $limit: 8 }, { $project: { "_id": 1, "title": 1, score: { $meta: "searchScore" } } } ])
{ "_id" : ObjectId("573a1396f29313caabce5646", "title" : "The Longest Yard", "score" : 2.914206027984619 } { "_id" : ObjectId("573a13aff29313caabd31ed8", "title" : "The Longest Yard", "score" : 2.914206027984619 } { "_id" : ObjectId("573a13b7f29313caabd4ad8b", "title" : "Stomp the Yard", "score" : 2.914206027984619 } { "_id" : ObjectId("573a13eaf29313caabdcf410", "title" : "Naz & Maalik", "score" : 2.5460386276245117 } { "_id" : ObjectId("573a1393f29313caabcddbed", "title" : "La nao capitana", "score" : 2.1892051696777344 } { "_id" : ObjectId("573a1399f29313caabcee781", "title" : "Kabhi Haan Kabhi Naa", "score" : 1.9200985431671143 } { "_id" : ObjectId("573a13a2f29313caabd0b815", "title" : "Kaho Naa... Pyaar Hai", "score" : 1.9200985431671143 } { "_id" : ObjectId("573a13a7f29313caabd1b5c0", "title" : "Oysters at Nam Kee's", "score" : 1.9200985431671143 }
Match all
The following query uses the text
operator to search the plot
field in the movies
collection for all the terms in the query string
automobile race
.
db.movies.aggregate([ { "$search": { "text": { "path": "plot", "query": "automobile race", "matchCriteria": "all" } } }, { "$limit": 20 }, { "$project": { "_id": 0, "plot": 1, "title": 1, "score": { "$meta": "searchScore" } } } ])
[ { plot: 'A young driver, Speed Racer, aspires to be champion of the racing world with the help of his family and his high-tech Mach 5 automobile.', title: 'Speed Racer', score: 6.122188568115234 }, { plot: 'A gorgeous young automobile fanatic--and front to the hottest unsigned band on the West coast--finds herself caught up in illegal drag-racing competitions organized by exotic car fanatics.', title: 'Redline', score: 5.497724533081055 }, { plot: 'When a popular daredevil proposes an automobile race across three continents, his arch rival vows to beat him, while an ambitious female reporter has her own plans for victory.', title: 'The Great Race', score: 5.282209396362305 } ]
Atlas Search returns documents that contain the terms automobile
and
race
anywhere in the plot
field.
Synonyms Examples
The following examples use the text
operator to search the
plot
field in the sample_mflix.movies
namespace. Atlas Search returns
results based on the type of mapping in the
synonym source collection,
synonymous_terms
, specified in the synonym mapping definition
of the index for the sample_mflix.movies
collection.
Match any
Using equivalent
Mapping
The following query searches the plot
field for the phrase
attire
. It uses the synonym mapping named mySynonyms
in
the index for the collection to also search for words that are
configured to be synonyms of the word dress
.
db.movies.aggregate([ { "$search": { "text": { "path": "plot", "query": "attire", "synonyms": "my_synonyms", "matchCriteria": "any" } } }, { "$limit": 5 }, { "$project": { "_id": 0, "plot": 1, "title": 1, "score": { "$meta": "searchScore" } } } ])
[ { plot: 'The Sanguiwon are responsible for the attire worn by royalty. Dol-Seok (Han Suk-Kyu) is the best master artisan in charge of royal attire. He views set rules as paramount to his job. ...', title: 'The Royal Tailor', score: 15.825017929077148 }, { plot: "During Christmas' holidays, the children of a village split in two gang to play a snowball war. But that half-tone war scattered some bitterness and make more difficult the mutual attirance...", title: 'La guerre des tuques', score: 11.863945007324219 }, { plot: 'The Dress is a tale filled with sex, violence, comedy and drama as it follows the life of a dress. Conceived under a cloud of frustration and despair, the dress serves as the hub in a great...', title: 'The Dress', score: 5.061710834503174 }, { plot: "Boardroom and dressing-room intrigues spill on to the field at the Australian Rules football club.", title: 'The Club', score: 3.991994857788086 }, { plot: 'Deserting soldier dresses as a woman to escape detection; liking the female role he goes to a dance with another soldier and is exposed.', title: 'The Triple Echo', score: 3.5169785022735596 } ]
Atlas Search returns the documents that contain the terms attire
,
apparel
, and dress
because we configured all these terms to be
equivalent
synonym in the synonyms source collection,
synonymous_terms
, which mean all these terms are synonyms of one
another. Therefore, Atlas Search returns similar documents for searches on
dress
and attire
.
Match any
Using explicit
Mapping
The following query searches the plot
field for the phrase boat
race
. It uses the synonym mapping named my_synonyms
in the index
for the collection to also search for words that are configured to be
synonyms of the word boat
and race
.
db.movies.aggregate([ { "$search": { "text": { "path": "plot", "query": "boat race", "synonyms": "my_synonyms", "matchCriteria": "any" } } }, { "$limit": 10 }, { "$project": { "_id": 0, "plot": 1, "title": 1, "score": { "$meta": "searchScore" } } } ])
[ { plot: 'A man is picked up by a fishing boat, bullet-riddled and suffering from amnesia, before racing to elude assassins and regain his memory.', title: 'The Bourne Identity', score: 15.405073165893555 }, { plot: 'A few friends builds a sailing boat together. They plan trips and during the completion of the boat marriages crumble, new relations blossom and the boat burns. They rebuild it and the ...', title: 's/y Glèdjen', score: 13.40434741973877 }, { plot: 'Famous motor-racing champion Joe Greer returns to his hometown to compete in a local race. He discovers his younger brother has aspirations to become a racing champion and during the race ...', title: 'The Crowd Roars', score: 10.466073036193848 }, { plot: 'The claustrophobic world of a WWII German U-boat; boredom, filth, and sheer terror.', title: 'Das Boot', score: 10.304922103881836 }, { plot: 'Several survivors of a torpedoed ship find themselves in the same boat with one of the men who sunk it.', title: 'Lifeboat', score: 9.776729583740234 }, { plot: 'A fishing-boat crew takes on a dangerous commission to smuggle a group of illegal immigrants from China to Korea.', title: 'Haemoo', score: 9.532430648803711 }, { plot: 'A land baron tries to reconnect with his two daughters after his wife is seriously injured in a boating accident.', title: 'The Descendants', score: 9.300044059753418 }, { plot: 'A weekend boating party turns into a nightmare for a group of young Londoners when they stumble upon a terrifying secret hidden in the reeds.', title: 'The Reeds', score: 9.078716278076172 }, { plot: 'Documentary telling the true story of the sinking of the liner Laconia by a German U-boat in 1942 through the eyes of six survivors.', title: 'The Sinking of the Laconia', score: 9.078716278076172 }, { plot: 'Sabotage efforts damage an international air race.', title: 'Those Magnificent Men in Their Flying Machines or How I Flew from London to Paris in 25 hours 11 minutes', score: 8.983794212341309 } ]
Atlas Search returns documents that contain the term boat
, vessel,
or
sail
, or race
, rally
, or contest
because we configured
boat
to be an explicit
synonym or vessel
and sail
and we
configured race
to be an explicit
synonym of rally
and
contest
. Atlas Search doesn't return any results for a query on vessel
and sail
or rally
and contest
because we didn't configure
these words to consider any of the other words as synonyms.
Match all
Using Synonyms
The following query uses the text
operator to search the plot
field in the movies
collection for all terms in the query string
automobile race
.
Atlas Search returns results based on the type of
mapping in the synonym source collection, synonymous_terms
, specified in the synonym
mapping definition of the index for the sample_mflix.movies
collection.
db.movies.aggregate([ { "$search": { "text": { "path": "plot", "query": "automobile race", "matchCriteria": "all", "synonyms": "my_synonyms" } } }, { "$limit": 20 }, { "$project": { "_id": 0, "plot": 1, "title": 1, "score": { "$meta": "searchScore" } } } ])
[ { plot: 'A young driver, Speed Racer, aspires to be champion of the racing world with the help of his family and his high-tech Mach 5 automobile.', title: 'Speed Racer', score: 17.354578018188477 }, { plot: 'A gorgeous young automobile fanatic--and front to the hottest unsigned band on the West coast--finds herself caught up in illegal drag-racing competitions organized by exotic car fanatics.', title: 'Redline', score: 16.085742950439453 }, { plot: 'When a popular daredevil proposes an automobile race across three continents, his arch rival vows to beat him, while an ambitious female reporter has her own plans for victory.', title: 'The Great Race', score: 15.087226867675781 }, { plot: 'A race car driver becomes a champion with a Volkswagen Beetle with a mind of its own.', title: 'The Love Bug', score: 5.1777167320251465 }, { plot: 'A wide variety of eccentric competitors participate in a wild and illegal cross-country car race.', title: 'The Cannonball Run', score: 5.041530609130859 }, { plot: 'The original characters from the first Cannonball movie race across the country once more in various cars and trucks.', title: 'Cannonball Run II', score: 4.67281436920166 }, { plot: 'After a tied 1st place in a local stunt race, two drivers start a contest to decide who of them will own the prize, a dune buggy. But when a mobster destroys the car, they are determined to get it back.', title: "Watch Out, We're Mad", score: 4.500225067138672 }, { plot: 'Four teenagers are killed in a car accident. Two of the teenagers refuse to go with "The Grim Reaper" and a race between life and death ensues!', title: 'Soultaker', score: 4.455573081970215 }, { plot: "The driver races to locate a kidnapped victim locked in the trunk of an abandoned car somewhere on the water's edge. Linked to her only by cell phone, the driver narrows in on her location in a desperate race against time and tide.", title: 'Hostage', score: 4.429774284362793 }, { plot: 'Race car driver Lucky Jackson goes to Las Vegas to earn money to pay for a new engine for his motor car. Working as a waiter, he still finds the time to court young Rusty Martin.', title: 'Viva Las Vegas', score: 4.379656791687012 }, { plot: 'Barry Pepper portrays legendary race car drive Dale Earnhardt, who died in 2001 during the last lap of the Daytona 500.', title: '3: The Dale Earnhardt Story', score: 4.3543548583984375 }, { plot: 'Bounty hunters from the future transport a doomed race-car driver to 2009 New York, where his mind will be replaced with that of a dead billionaire.', title: 'Freejack', score: 4.257633209228516 }, { plot: 'A mechanic takes his family to a car race and a series of events occur which brings problems, betrayals, violence and the unexpected death of an elderly person.', title: 'National Mechanics', score: 4.257633209228516 }, { plot: 'A hot-shot race-car named Lightning McQueen gets waylaid in Radiator Springs, where he finds the true meaning of friendship and family.', title: 'Cars', score: 4.257633209228516 }, { plot: 'Star race car Lightning McQueen and his pal Mater head overseas to compete in the World Grand Prix race. But the road to the championship becomes rocky as Mater gets caught up in an intriguing adventure of his own: international espionage.', title: 'Cars 2', score: 4.231379985809326 }, { plot: "An illegal race that takes place over the United States and nothing will stop this bunch of racers except for the occasional cop or a damsel in distress. Jackie Chan's car is not in this ...", title: 'Cannonball Fever', score: 4.1651153564453125 }, { plot: 'Roy is mad about cars, and runs Stallion Parts while attending to his yellow Mustang, far away from his daughter, which comes on holiday, while he is to attend a race. Soon he is challenged in a illegal race through the length of Norway.', title: 'Bèrning', score: 4.050384521484375 }, { plot: "It's time for the annual London to Brighton antique car rally, and Alan McKim and Ambrose Claverhouse are not going to let their friendship stop them from trying to humiliate each other. ...", title: 'Genevieve', score: 3.9916391372680664 }, { plot: "After a young man's premonition of a deadly race-car crash helps saves the lives of his peers, Death sets out to collect those who evaded their end.", title: 'The Final Destination', score: 3.9916391372680664 }, { plot: "A fast-paced comedy about a young Belgian car nut and hairdresser's apprentice, his girlfriend, and their legal and illegal attempts to get a Porsche under him for his nearing debut race.", title: 'The Departure', score: 3.832036256790161 } ]
Atlas Search returns documents that contain the query terms automobile
,
car
, or vehicle
and race
, context
, or rally
because
we configured automobile
, vehicle
, and car
to be
equivalent
synonyms and we configured rally
and contest
to
be explicit
synonyms of race
in the synonymous_terms
collection.