Query string query
editQuery string query
editReturns documents based on a provided query string, using a parser with a strict syntax.
This query uses a syntax to parse and split the provided
query string based on operators, such as AND
or NOT
. The query
then analyzes each split text independently before returning
matching documents.
You can use the query_string
query to create a complex search that includes
wildcard characters, searches across multiple fields, and more. While versatile,
the query is strict and returns an error if the query string includes any
invalid syntax.
Because it returns an error for any invalid syntax, we don’t recommend using
the query_string
query for search boxes.
If you don’t need to support a query syntax, consider using the
match
query. If you need the features of a query
syntax, use the simple_query_string
query, which is less strict.
Example request
editWhen running the following search, the query_string
query splits (new york
city) OR (big apple)
into two parts: new york city
and big apple
. The
content
field’s analyzer then independently converts each part into tokens
before returning matching documents. Because the query syntax does not use
whitespace as an operator, new york city
is passed as-is to the analyzer.
GET /_search { "query": { "query_string" : { "query" : "(new york city) OR (big apple)", "default_field" : "content" } } }
Top-level parameters for query_string
edit-
query
- (Required, string) Query string you wish to parse and use for search. See Query string syntax.
-
default_field
-
(Optional, string) Default field you wish to search if no field is provided in the query string.
Defaults to the
index.query.default_field
index setting, which has a default value of*
. The*
value extracts all fields that are eligible to term queries and filters the metadata fields. All extracted fields are then combined to build a query if noprefix
is specified.There is a limit on the number of fields that can be queried at once. It is defined by the
indices.query.bool.max_clause_count
search setting, which defaults to 1024. -
allow_leading_wildcard
-
(Optional, boolean) If
true
, the wildcard characters*
and?
are allowed as the first character of the query string. Defaults totrue
. -
analyze_wildcard
-
(Optional, boolean) If
true
, the query attempts to analyze wildcard terms in the query string. Defaults tofalse
. -
analyzer
-
(Optional, string) Analyzer used to convert text in the
query string into tokens. Defaults to the
index-time analyzer mapped for the
default_field
. If no analyzer is mapped, the index’s default analyzer is used. -
auto_generate_synonyms_phrase_query
-
(Optional, boolean) If
true
, match phrase queries are automatically created for multi-term synonyms. Defaults totrue
. See Synonyms and thequery_string
query for an example. -
boost
-
(Optional, float) Floating point number used to decrease or increase the relevance scores of the query. Defaults to
1.0
.Boost values are relative to the default value of
1.0
. A boost value between0
and1.0
decreases the relevance score. A value greater than1.0
increases the relevance score. -
default_operator
-
(Optional, string) Default boolean logic used to interpret text in the query string if no operators are specified. Valid values are:
-
OR
(Default) -
For example, a query string of
capital of Hungary
is interpreted ascapital OR of OR Hungary
. -
AND
-
For example, a query string of
capital of Hungary
is interpreted ascapital AND of AND Hungary
.
-
-
enable_position_increments
-
(Optional, boolean) If
true
, enable position increments in queries constructed from aquery_string
search. Defaults totrue
. -
fields
-
(Optional, array of strings) Array of fields you wish to search.
You can use this parameter query to search across multiple fields. See Search multiple fields.
-
fuzziness
- (Optional, string) Maximum edit distance allowed for matching. See Fuzziness for valid values and more information.
-
fuzzy_max_expansions
-
(Optional, integer) Maximum number of terms to which the query expands for fuzzy
matching. Defaults to
50
. -
fuzzy_prefix_length
-
(Optional, integer) Number of beginning characters left unchanged for fuzzy
matching. Defaults to
0
. -
fuzzy_transpositions
-
(Optional, boolean) If
true
, edits for fuzzy matching include transpositions of two adjacent characters (ab → ba). Defaults totrue
. -
lenient
-
(Optional, boolean) If
true
, format-based errors, such as providing a text value for a numeric field, are ignored. Defaults tofalse
. -
max_determinized_states
-
(Optional, integer) Maximum number of automaton states required for the query. Default is
10000
.Elasticsearch uses Apache Lucene internally to parse regular expressions. Lucene converts each regular expression to a finite automaton containing a number of determinized states.
You can use this parameter to prevent that conversion from unintentionally consuming too many resources. You may need to increase this limit to run complex regular expressions.
-
minimum_should_match
-
(Optional, string) Minimum number of clauses that must match for a document to
be returned. See the
minimum_should_match
parameter for valid values and more information. See Howminimum_should_match
works for an example. -
quote_analyzer
-
(Optional, string) Analyzer used to convert quoted text in the query string into tokens. Defaults to the
search_quote_analyzer
mapped for thedefault_field
.For quoted text, this parameter overrides the analyzer specified in the
analyzer
parameter. -
phrase_slop
-
(Optional, integer) Maximum number of positions allowed between matching tokens
for phrases. Defaults to
0
. If0
, exact phrase matches are required. Transposed terms have a slop of2
. -
quote_field_suffix
-
(Optional, string) Suffix appended to quoted text in the query string.
You can use this suffix to use a different analysis method for exact matches. See Mixing exact search with stemming.
-
rewrite
-
(Optional, string) Method used to rewrite the query. For valid values and more
information, see the
rewrite
parameter. -
time_zone
-
(Optional, string) Coordinated Universal Time (UTC) offset or IANA time zone used to convert
date
values in the query string to UTC.Valid values are ISO 8601 UTC offsets, such as
+01:00
or -08:00
, and IANA time zone IDs, such asAmerica/Los_Angeles
.The
time_zone
parameter does not affect the date math value ofnow
.now
is always the current system time in UTC. However, thetime_zone
parameter does convert dates calculated usingnow
and date math rounding. For example, thetime_zone
parameter will convert a value ofnow/d
.
Notes
editQuery string syntax
editThe query string “mini-language” is used by the
Query string and by the
q
query string parameter in the search
API.
The query string is parsed into a series of terms and operators. A
term can be a single word — quick
or brown
— or a phrase, surrounded by
double quotes — "quick brown"
— which searches for all the words in the
phrase, in the same order.
Operators allow you to customize the search — the available options are explained below.
Field names
editYou can specify fields to search in the query syntax:
-
where the
status
field containsactive
status:active
-
where the
title
field containsquick
orbrown
title:(quick OR brown)
-
where the
author
field contains the exact phrase"john smith"
author:"John Smith"
-
where the
first name
field containsAlice
(note how we need to escape the space with a backslash)first\ name:Alice
-
where any of the fields
book.title
,book.content
orbook.date
containsquick
orbrown
(note how we need to escape the*
with a backslash):book.\*:(quick OR brown)
-
where the field
title
has any non-null value:_exists_:title
Wildcards
editWildcard searches can be run on individual terms, using ?
to replace
a single character, and *
to replace zero or more characters:
qu?ck bro*
Be aware that wildcard queries can use an enormous amount of memory and
perform very badly — just think how many terms need to be queried to
match the query string "a* b* c*"
.
Pure wildcards \*
are rewritten to exists
queries for efficiency.
As a consequence, the wildcard "field:*"
would match documents with an empty value
like the following:
{ "field": "" }
... and would not match if the field is missing or set with an explicit null value like the following:
{ "field": null }
Allowing a wildcard at the beginning of a word (eg "*ing"
) is particularly
heavy, because all terms in the index need to be examined, just in case
they match. Leading wildcards can be disabled by setting
allow_leading_wildcard
to false
.
Only parts of the analysis chain that operate at the character level are applied. So for instance, if the analyzer performs both lowercasing and stemming, only the lowercasing will be applied: it would be wrong to perform stemming on a word that is missing some of its letters.
By setting analyze_wildcard
to true, queries that end with a *
will be
analyzed and a boolean query will be built out of the different tokens, by
ensuring exact matches on the first N-1 tokens, and prefix match on the last
token.
Regular expressions
editRegular expression patterns can be embedded in the query string by
wrapping them in forward-slashes ("/"
):
name:/joh?n(ath[oa]n)/
The supported regular expression syntax is explained in Regular expression syntax.
The allow_leading_wildcard
parameter does not have any control over
regular expressions. A query string such as the following would force
Elasticsearch to visit every term in the index:
/.*n/
Use with caution!
Fuzziness
editWe can search for terms that are similar to, but not exactly like our search terms, using the “fuzzy” operator:
quikc~ brwn~ foks~
This uses the Damerau-Levenshtein distance to find all terms with a maximum of two changes, where a change is the insertion, deletion or substitution of a single character, or transposition of two adjacent characters.
The default edit distance is 2
, but an edit distance of 1
should be
sufficient to catch 80% of all human misspellings. It can be specified as:
quikc~1
Proximity searches
editWhile a phrase query (eg "john smith"
) expects all of the terms in exactly
the same order, a proximity query allows the specified words to be further
apart or in a different order. In the same way that fuzzy queries can
specify a maximum edit distance for characters in a word, a proximity search
allows us to specify a maximum edit distance of words in a phrase:
"fox quick"~5
The closer the text in a field is to the original order specified in the
query string, the more relevant that document is considered to be. When
compared to the above example query, the phrase "quick fox"
would be
considered more relevant than "quick brown fox"
.
Ranges
editRanges can be specified for date, numeric or string fields. Inclusive ranges
are specified with square brackets [min TO max]
and exclusive ranges with
curly brackets {min TO max}
.
-
All days in 2012:
date:[2012-01-01 TO 2012-12-31]
-
Numbers 1..5
count:[1 TO 5]
-
Tags between
alpha
andomega
, excludingalpha
andomega
:tag:{alpha TO omega}
-
Numbers from 10 upwards
count:[10 TO *]
-
Dates before 2012
date:{* TO 2012-01-01}
Curly and square brackets can be combined:
-
Numbers from 1 up to but not including 5
count:[1 TO 5}
Ranges with one side unbounded can use the following syntax:
age:>10 age:>=10 age:<10 age:<=10
To combine an upper and lower bound with the simplified syntax, you
would need to join two clauses with an AND
operator:
age:(>=10 AND <20) age:(+>=10 +<20)
The parsing of ranges in query strings can be complex and error prone. It is
much more reliable to use an explicit range
query.
Boosting
editUse the boost operator ^
to make one term more relevant than another.
For instance, if we want to find all documents about foxes, but we are
especially interested in quick foxes:
quick^2 fox
The default boost
value is 1, but can be any positive floating point number.
Boosts between 0 and 1 reduce relevance.
Boosts can also be applied to phrases or to groups:
"john smith"^2 (foo bar)^4
Boolean operators
editBy default, all terms are optional, as long as one term matches. A search
for foo bar baz
will find any document that contains one or more of
foo
or bar
or baz
. We have already discussed the default_operator
above which allows you to force all terms to be required, but there are
also boolean operators which can be used in the query string itself
to provide more control.
The preferred operators are +
(this term must be present) and -
(this term must not be present). All other terms are optional.
For example, this query:
quick brown +fox -news
states that:
-
fox
must be present -
news
must not be present -
quick
andbrown
are optional — their presence increases the relevance
The familiar boolean operators AND
, OR
and NOT
(also written &&
, ||
and !
) are also supported but beware that they do not honor the usual
precedence rules, so parentheses should be used whenever multiple operators are
used together. For instance the previous query could be rewritten as:
-
((quick AND fox) OR (brown AND fox) OR fox) AND NOT news
- This form now replicates the logic from the original query correctly, but the relevance scoring bears little resemblance to the original.
In contrast, the same query rewritten using the match
query
would look like this:
{ "bool": { "must": { "match": "fox" }, "should": { "match": "quick brown" }, "must_not": { "match": "news" } } }
Grouping
editMultiple terms or clauses can be grouped together with parentheses, to form sub-queries:
(quick OR brown) AND fox
Groups can be used to target a particular field, or to boost the result of a sub-query:
status:(active OR pending) title:(full text search)^2
Reserved characters
editIf you need to use any of the characters which function as operators in your
query itself (and not as operators), then you should escape them with
a leading backslash. For instance, to search for (1+1)=2
, you would
need to write your query as \(1\+1\)\=2
. When using JSON for the request body, two preceding backslashes (\\
) are required; the backslash is a reserved escaping character in JSON strings.
GET /twitter/_search { "query" : { "query_string" : { "query" : "kimchy\\!", "fields" : ["user"] } } }
The reserved characters are: + - = && || > < ! ( ) { } [ ] ^ " ~ * ? : \ /
Failing to escape these special characters correctly could lead to a syntax error which prevents your query from running.
<
and >
can’t be escaped at all. The only way to prevent them from
attempting to create a range query is to remove them from the query string
entirely.
Whitespaces and empty queries
editWhitespace is not considered an operator.
If the query string is empty or only contains whitespaces the query will yield an empty result set.
Avoid using the query_string
query for nested documents
editquery_string
searches do not return nested documents. To search
nested documents, use the nested
query.
Search multiple fields
editYou can use the fields
parameter to perform a query_string
search across
multiple fields.
The idea of running the query_string
query against multiple fields is to
expand each query term to an OR clause like this:
field1:query_term OR field2:query_term | ...
For example, the following query
GET /_search { "query": { "query_string" : { "fields" : ["content", "name"], "query" : "this AND that" } } }
matches the same words as
GET /_search { "query": { "query_string": { "query": "(content:this OR name:this) AND (content:that OR name:that)" } } }
Since several queries are generated from the individual search terms,
combining them is automatically done using a dis_max
query with a tie_breaker
.
For example (the name
is boosted by 5 using ^5
notation):
GET /_search { "query": { "query_string" : { "fields" : ["content", "name^5"], "query" : "this AND that OR thus", "tie_breaker" : 0 } } }
Simple wildcard can also be used to search "within" specific inner
elements of the document. For example, if we have a city
object with
several fields (or inner object with fields) in it, we can automatically
search on all "city" fields:
GET /_search { "query": { "query_string" : { "fields" : ["city.*"], "query" : "this AND that OR thus" } } }
Another option is to provide the wildcard fields search in the query
string itself (properly escaping the *
sign), for example:
city.\*:something
:
GET /_search { "query": { "query_string" : { "query" : "city.\\*:(this AND that OR thus)" } } }
Since \
(backslash) is a special character in json strings, it needs to
be escaped, hence the two backslashes in the above query_string
.
The fields parameter can also include pattern based field names, allowing to automatically expand to the relevant fields (dynamically introduced fields included). For example:
GET /_search { "query": { "query_string" : { "fields" : ["content", "name.*^5"], "query" : "this AND that OR thus" } } }
Additional parameters for multiple field searches
editWhen running the query_string
query against multiple fields, the
following additional parameters are supported.
-
type
-
(Optional, string) Determines how the query matches and scores documents. Valid values are:
-
best_fields
(Default) -
Finds documents which match any field and uses the highest
_score
from any matching field. Seebest_fields
. -
bool_prefix
-
Creates a
match_bool_prefix
query on each field and combines the_score
from each field. Seebool_prefix
. -
cross_fields
-
Treats fields with the same
analyzer
as though they were one big field. Looks for each word in any field. Seecross_fields
. -
most_fields
-
Finds documents which match any field and combines the
_score
from each field. Seemost_fields
. -
phrase
-
Runs a
match_phrase
query on each field and uses the_score
from the best field. Seephrase
andphrase_prefix
. -
phrase_prefix
-
Runs a
match_phrase_prefix
query on each field and uses the_score
from the best field. Seephrase
andphrase_prefix
.
NOTE: Additional top-level
multi_match
parameters may be available based on thetype
value. -
Synonyms and the query_string
query
editThe query_string
query supports multi-terms synonym expansion with the synonym_graph token filter. When this filter is used, the parser creates a phrase query for each multi-terms synonyms.
For example, the following synonym: ny, new york
would produce:
(ny OR ("new york"))
It is also possible to match multi terms synonyms with conjunctions instead:
GET /_search { "query": { "query_string" : { "default_field": "title", "query" : "ny city", "auto_generate_synonyms_phrase_query" : false } } }
The example above creates a boolean query:
(ny OR (new AND york)) city
that matches documents with the term ny
or the conjunction new AND york
.
By default the parameter auto_generate_synonyms_phrase_query
is set to true
.
How minimum_should_match
works
editThe query_string
splits the query around each operator to create a boolean
query for the entire input. You can use minimum_should_match
to control how
many "should" clauses in the resulting query should match.
GET /_search { "query": { "query_string": { "fields": [ "title" ], "query": "this that thus", "minimum_should_match": 2 } } }
The example above creates a boolean query:
(title:this title:that title:thus)~2
that matches documents with at least two of the terms this
, that
or thus
in the single field title
.
How minimum_should_match
works for multiple fields
editGET /_search { "query": { "query_string": { "fields": [ "title", "content" ], "query": "this that thus", "minimum_should_match": 2 } } }
The example above creates a boolean query:
((content:this content:that content:thus) | (title:this title:that title:thus))
that matches documents with the disjunction max over the fields title
and
content
. Here the minimum_should_match
parameter can’t be applied.
GET /_search { "query": { "query_string": { "fields": [ "title", "content" ], "query": "this OR that OR thus", "minimum_should_match": 2 } } }
Adding explicit operators forces each term to be considered as a separate clause.
The example above creates a boolean query:
((content:this | title:this) (content:that | title:that) (content:thus | title:thus))~2
that matches documents with at least two of the three "should" clauses, each of them made of the disjunction max over the fields for each term.
How minimum_should_match
works for cross-field searches
editA cross_fields
value in the type
field indicates fields with the same
analyzer are grouped together when the input is analyzed.
GET /_search { "query": { "query_string": { "fields": [ "title", "content" ], "query": "this OR that OR thus", "type": "cross_fields", "minimum_should_match": 2 } } }
The example above creates a boolean query:
(blended(terms:[field2:this, field1:this]) blended(terms:[field2:that, field1:that]) blended(terms:[field2:thus, field1:thus]))~2
that matches documents with at least two of the three per-term blended queries.