text¶

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Definition

Syntax
Fields
Examples
Basic Example
Fuzzy Examples
Synonyms Examples

Definition¶

The text operator performs a full-text search using the analyzer specified in the index configuration. If you do not specify an analyzer, the default standard analyzer is used.

Syntax¶

text has the following syntax:

{
  $search: {
    "index": <index name>, // optional, defaults to "default"
    "text": {
      "query": "<search-string>",
      "path": "<field-to-search>",
      "fuzzy": <options>,
      "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 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	The maximum number of variations to generate and search for. This limit applies on a per-token basis. The default value is `50`.	Optional
`score`	document	The score assigned to matching search term results. Use one of the following options to modify the score: `boost`: multiply the result score by the given number. `constant`: replace the result score with the given number.	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 `fuzzy` with `synonyms`.	Optional

Examples¶

The Basic and Fuzzy examples below use the movies collection in the sample_mflix database. After loading the sample dataset into your cluster, create the Atlas Search index on the title field and run the example queries on your cluster.

Tip

If you've already loaded the sample dataset, follow the Get Started with Atlas Search tutorial to create an index definition and run Atlas Search queries.

The Synonyms examples below use the user_feedback.comments and user_feedback.synonyms collections and the index definition described in Define Synonym Mappings. After loading the user_feedback.comments and user_feedback.synonyms collections and configuring the index definition for the collection, you can run the queries 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" }
    }
  }
])

The above query returns the following results:

{ "title" : "Soul Surfer", "score" : 4.572484970092773 }
{ "title" : "Little Surfer Girl", "score" : 3.9323642253875732 }
{ "title" : "Fantastic 4: Rise of the Silver Surfer", "score" : 2.520784616470337 }

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:

Synonyms Examples¶

The following examples use the text operator to search the comments field in the user_feedback.comments collection. Atlas Search returns results based on the type of mapping in the synonym source collection, user_feedback.synonyms, specified in the synonym mapping definition of the index for the user_feedback.comments collection.

Note

To learn more about the user_feedback.comments and user_feedback.synonyms collections and the index definition for the user_feedback.comments collection, see Example in the Define Synonym Mappings in Your Atlas Search Index page.

`equivalent` Mapping Example¶

The following query searches the comments field for the word dress. 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.comments.aggregate([
  {
    $search: {
      "text": {
        "path": "comments",
        "query": "dress",
        "synonyms": "mySynonyms"
      }
    }
  }
])

The preceding query returns the following results:

{
  "_id" : ObjectId("60e5f7d65f32d78cb3a3cc7a"),
  "type" : "apparel store",
  "comments" : "Beautiful apparel for the bride."
}

Atlas Search returns the above document because dress is configured to be synonym of apparel and attire using equivalent mappings in the synonym source collection, user_feedback.synonyms. Atlas Search returns the above document for searches on apparel and attire also because all three words are configured to be synonyms of one another in the synonym source collection.

`explicit` Mapping Example¶

The following query searches the comments field for the word boat. 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 boat.

db.comments.aggregate([
  {
    $search: {
      "text": {
        "path": "comments",
        "query": "boat",
        "synonyms": "mySynonyms"
      }
    }
  }
])