Text Search

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Overview

MongoDB supports query operations that perform a text search of string content. To perform text search, MongoDB uses atext indexand the$textoperator.

NOTE

Viewsdo not support text search.

Example

This example demonstrates how to build a text index and use it to find coffee shops, given only text fields.

Create a collectionstoreswith the following documents:

  1. db.stores.insert(
  2. [
  3. { _id: 1, name: "Java Hut", description: "Coffee and cakes" },
  4. { _id: 2, name: "Burger Buns", description: "Gourmet hamburgers" },
  5. { _id: 3, name: "Coffee Shop", description: "Just coffee" },
  6. { _id: 4, name: "Clothes Clothes Clothes", description: "Discount clothing" },
  7. { _id: 5, name: "Java Shopping", description: "Indonesian goods" }
  8. ]
  9. )

Text Index

MongoDB providestext indexesto support text search queries on string content.textindexes can include any field whose value is a string or an array of string elements.

To perform text search queries, you must have atextindex on your collection. A collection can only haveonetext search index, but that index can cover multiple fields.

For example you can run the following in amongoshell to allow text search over thenameanddescriptionfields:db

  1. db.stores.createIndex( { name: "text", description: "text" } )

$textOperator

Use the$textquery operator to perform text searches on a collection with atext index.

$textwill tokenize the search string using whitespace and most punctuation as delimiters, and perform a logicalORof all such tokens in the search string.

For example, you could use the following query to find all stores containing any terms from the list “coffee”, “shop”, and “java”:

  1. db.stores.find( { $text: { $search: "java coffee shop" } } )

Exact Phrase

You can also search for exact phrases by wrapping them in double-quotes. For example, the following will find all documents containing “java” or “coffee shop”:

  1. db.stores.find( { $text: { $search: "java \"coffee shop\"" } } )

Term Exclusion

To exclude a word, you can prepend a “-” character. For example, to find all stores containing “java” or “shop” but not “coffee”, use the following:db

  1. db.stores.find( { $text: { $search: "java shop -coffee" } } )

Sorting

MongoDB will return its results in unsorted order by default. However, text search queries will compute a relevance score for each document that specifies how well a document matches the query.

To sort the results in order of relevance score, you must explicitly project the$metatextScorefield and sort on it:

  1. db.stores.find(
  2. { $text: { $search: "java coffee shop" } },
  3. { score: { $meta: "textScore" } }
  4. ).sort( { score: { $meta: "textScore" } } )

Text search is also available in the aggregation pipeline.

Language Support

MongoDB supports text search for various languages. SeeText Search Languagesfor a list of supported languages.