Hướng dẫn wildcard search mongodb

The wildcard operator enables queries which use special characters in the search string that can match any character.

wildcard is a term-level operator, meaning that the query field is not analyzed. Term-level operators work well with the Keyword Analyzer, because the query field is treated as a single term, with special characters included. For an example of querying against an analyzed query field vs. a non-analyzed query field, see the analyzed field example.

wildcard has the following syntax:

{
  $search: {
    "index": , // optional, defaults to "default"
    "wildcard": {
      "query": "",
      "path": "",
      "allowAnalyzedField": ,
      "score": 
    }
  }
}

wildcard uses the following terms to construct a query:

wildcard is a term-level operator, meaning that the query field is not analyzed. It is possible to use the wildcard operator to perform searches on a field analyzed during indexing by setting the allowAnalyzedField option to true, but results will reflect that the query text is not analyzed.

Example

Suppose that a field foo bar baz is indexed with the standard analyzer. Atlas Search analyzes and indexes the field as foo, bar and baz. Searching for foo bar* on this field finds nothing, because the wildcard operator treats foo bar* as a single search term with a wildcard at the end. In other words, Atlas Search searches the field for any term that begins with foo bar but finds nothing, because no term exists.

Example

Searching for *Star Trek* on a field indexed with the keyword analyzer finds all documents in which the field contains the string Star Trek in any context. Searching for *Star Trek* on a field indexed with the standard analyzer finds nothing, because there is a space between Star and Trek, and the index contains no spaces.

The following examples use the movies collection in the sample_mflix database with a custom index definition that uses the keyword analyzer. If you have the sample dataset on your cluster, you can create an Atlas Search index on the movies collection and run the example queries on your cluster.

Tip

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{
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  "mappings": {
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    "fields": {
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      "title": {
5
        "analyzer": "lucene.keyword",
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        "type": "string"
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      }
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    }
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  }
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}