Simple query string query

Use the simple_query_string type to specify multiple arguments delineated by regular expressions directly in the query string. Simple query string has a less strict syntax than query string because it discards any invalid portions of the string and does not return errors for invalid syntax.

This query uses a simple syntax to parse the query string based on special operators and split the string into terms. After parsing, the query analyzes each term independently and then returns matching documents.

The following query performs fuzzy search on the title field:

GET _search
{
  "query": {
    "simple_query_string": {
      "query": "\"rises wind the\"~4 | *ising~2",
      "fields": ["title"]
    }
  }
}

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Simple query string syntax

A query string consists of terms and operators. A term is a single word (for example, in the query wind rises, the terms are wind and rises). If several terms are surrounded by quotation marks, they are treated as one phrase where words are marched in the order they appear (for example, "wind rises"). Operators such as +, |, and - specify the Boolean logic used to interpret text in the query string.

Operators

Simple query string syntax supports the following operators.

All of the preceding operators are reserved characters. To refer to them as raw characters and not operators, escape any of them with a backslash. When sending a JSON request, use \\ to escape reserved characters (because the backslash character is itself reserved, you must escape the backslash with another backslash).

Default operator

The default operator is OR (unless you set the default_operator to AND). The default operator dictates the overall query behavior. For example, consider an index containing the following documents:

PUT /customers/_doc/1
{
  "first_name":"Amber",
  "last_name":"Duke",
  "address":"880 Holmes Lane"
}

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PUT /customers/_doc/2
{
  "first_name":"Hattie",
  "last_name":"Bond",
  "address":"671 Bristol Street"
}

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PUT /customers/_doc/3
{
  "first_name":"Nanette",
  "last_name":"Bates",
  "address":"789 Madison St"
}

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PUT /customers/_doc/4
{
  "first_name":"Dale",
  "last_name":"Amber",
  "address":"467 Hutchinson Court"
}

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The following query attempts to find documents, for which the address contains the words street or st and does not contain the word madison:

GET /customers/_search
{
  "query": {
    "simple_query_string": {
      "fields": [ "address" ],
      "query": "street st -madison"
    }
  }
}

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However, the results include not only the expected document, but all four documents:

Response

{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 4,
      "relation": "eq"
    },
    "max_score": 2.2039728,
    "hits": [
      {
        "_index": "customers",
        "_id": "2",
        "_score": 2.2039728,
        "_source": {
          "first_name": "Hattie",
          "last_name": "Bond",
          "address": "671 Bristol Street"
        }
      },
      {
        "_index": "customers",
        "_id": "3",
        "_score": 1.2039728,
        "_source": {
          "first_name": "Nanette",
          "last_name": "Bates",
          "address": "789 Madison St"
        }
      },
      {
        "_index": "customers",
        "_id": "1",
        "_score": 1,
        "_source": {
          "first_name": "Amber",
          "last_name": "Duke",
          "address": "880 Holmes Lane"
        }
      },
      {
        "_index": "customers",
        "_id": "4",
        "_score": 1,
        "_source": {
          "first_name": "Dale",
          "last_name": "Amber",
          "address": "467 Hutchinson Court"
        }
      }
    ]
  }
}

Because the default operator is OR, this query includes documents that contain the words street or st (documents 2 and 3) and documents that do not contain the word madison (documents 1 and 4).

To express the query intent correctly, precede -madison with +:

GET /customers/_search
{
  "query": {
    "simple_query_string": {
      "fields": [ "address" ],
      "query": "street st +-madison"
    }
  }
}

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Alternatively, specify AND as the default operator and use disjunction for the words street and st:

GET /customers/_search
{
  "query": {
    "simple_query_string": {
      "fields": [ "address" ],
      "query": "st|street -madison",
      "default_operator": "AND"
    }
  }
}

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The preceding query returns document 2:

Response

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 2.2039728,
    "hits": [
      {
        "_index": "customers",
        "_id": "2",
        "_score": 2.2039728,
        "_source": {
          "first_name": "Hattie",
          "last_name": "Bond",
          "address": "671 Bristol Street"
        }
      }
    ]
  }
}

Limit operators

To limit the supported operators for the simple query string parser, include the operators that you want to support, separated by |, in the flags parameter. For example, the following query enables only OR, AND, and FUZZY operators:

GET /customers/_search
{
  "query": {
    "simple_query_string": {
      "fields": [ "address" ],
      "query": "bristol | madison +stre~2",
      "flags": "OR|AND|FUZZY"
    }
  }
}

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The following table lists all available operator flags.

Wildcard expressions

You can specify wildcard expressions using the * special character, which replaces zero or more characters. For example, the following query searches in all fields that end with name:

GET /customers/_search
{
  "query": {
    "simple_query_string" : {
      "query":    "Amber Bond",
      "fields": [ "*name" ] 
    }
  }
}

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Boosting

Use the caret (^) boost operator to boost the relevance score of a field by a multiplier. Values in the [0, 1) range decrease relevance, and values greater than 1 increase relevance. Default is 1.

For example, the following query searches the first_name and last_name fields and boosts matches from the first_name field by a factor of 2:

GET /customers/_search
{
  "query": {
    "simple_query_string" : {
      "query":    "Amber",
      "fields": [ "first_name^2", "last_name" ] 
    }
  }
}

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Multi-position tokens

For multi-position tokens, simple query string creates a match phrase query. Thus, if you specify ml, machine learning as synonyms and search for ml, OpenSearch searches for ml OR "machine learning".

Alternatively, you can match multi-position tokens using conjunctions. If you set auto_generate_synonyms_phrase_query to false, OpenSearch searches for ml OR (machine AND learning).

For example, the following query searches for the text ml models and specifies not to auto-generate a match phrase query for each synonym:

GET /testindex/_search
{
  "query": {
    "simple_query_string": {
      "fields": ["title"],
      "query": "ml models",
      "auto_generate_synonyms_phrase_query": false
    }
  }
}

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For this query, OpenSearch creates the following Boolean query: (ml OR (machine AND learning)) models.

Parameters

The following table lists the top-level parameters that simple_query_string query supports. All parameters except query are optional.