The MATCH
clause allows to perform full-text searches in text fields. The query string at input is tokenized using same settings applied to the text during indexing. In addition to tokenization of input text, the query string supports a number of full-text operators that allow enforcing different rules on how keywords should provide a valid match.
The full-text match clauses can be combined with attribute filters as an AND boolean. OR relation between full-text matches and attribute filters are not supported.
The match query is always executed first in the filtering process, followed by the attribute filters. The attribute filters are applied on the result set of the match query. A query without a match clause is called a fullscan.
There must be at most one MATCH()
in the SELECT
clause.
Using the full-text query syntax matching is performed over all indexed text fields of a document, unless the expression requires to be match within a field (like phrase search) or limited by field operators.
SELECT * FROM index WHERE MATCH('cats|birds');
SELECT statement uses MATCH clause for performing full-text searches. It accepts an input string in which all full-text operators are available.
- SQL
SELECT * FROM myindex WHERE MATCH('"find me fast"/2');
+------+------+----------------+
| id | gid | title |
+------+------+----------------+
| 1 | 11 | first find me |
| 2 | 12 | second find me |
+------+------+----------------+
2 rows in set (0.00 sec)
Full-text matching is available in the /search
endpoint and in HTTP-based clients. The following clauses can be used for performing full-text matches:
"match" is a simple query that matches the specified keywords in the specified fields
"query":
{
"match": { "field": "keyword" }
}
You can specify a list of fields:
"match":
{
"field1,field2": "keyword"
}
Or you can use _all
or *
to search all fields.
You can search all fields except one using "!field":
"match":
{
"!field1": "keyword"
}
By default keywords are combined using the OR operator. However, you can change that behaviour using the "operator" clause:
"query":
{
"match":
{
"content,title":
{
"query":"keyword",
"operator":"or"
}
}
}
"operator" can be set to "or" or "and".
"match_phrase" is a query that matches the entire phrase. It is similar to a phrase operator in SQL. Here's an example:
"query":
{
"match_phrase": { "_all" : "had grown quite" }
}
"query_string" accepts an input string as a full-text query in MATCH()
syntax
"query":
{
"query_string": "Church NOTNEAR/3 street"
}
All full-text match clauses can be combined with must, must_not and should operators of an HTTP bool
query.
- match
- match_phrase
- query_string
- PHP
- Python
- javascript
- Java
POST /search
-d
'{
"index" : "hn_small",
"query":
{
"match":
{
"*" : "find joe"
}
},
"_source": ["story_author","comment_author"],
"limit": 1
}'
{
"took" : 3,
"timed_out" : false,
"hits" : {
"hits" : [
{
"_id" : "668018",
"_score" : 3579,
"_source" : {
"story_author" : "IgorPartola",
"comment_author" : "joe_the_user"
}
}
],
"total" : 88063,
"total_relation" : "eq"
}
}
The query string can contain certain operators that allow telling the conditions of how the words from the query string should be matched.
There always is implicit AND
operator, so "hello world" means that both "hello" and "world" must be present in matching document.
hello world
OR
operator precedence is higher than AND, so looking for cat | dog | mouse
means looking for ( cat | dog | mouse )
and not (looking for cat) | dog | mouse
.
hello | world
hello MAYBE world
MAYBE
operator works much like operator |
but doesn't return documents which match only right subtree expression.
hello -world
hello !world
The negation operator enforces a rule for a word to not exist.
Queries having only negations are not supported by default in Manticore Search. There's the server option not_terms_only_allowed to enable it.
@title hello @body world
Field limit operator limits subsequent searching to a given field. Normally, query will fail with an error message if given field name does not exist in the searched table. However, that can be suppressed by specifying @@relaxed
option at the very beginning of the query:
@@relaxed @nosuchfield my query
This can be helpful when searching through heterogeneous tables with different schemas.
Field position limit additionally restricts the searching to first N position within given field (or fields). For example, @body [50] hello
will not match the documents where the keyword hello
occurs at position 51 and below in the body.
@body[50] hello
Multiple-field search operator:
@(title,body) hello world
Ignore field search operator (will ignore any matches of 'hello world' from field 'title'):
@!title hello world
Ignore multiple-field search operator (if we have fields title,
subject and body then @!(title)
is equivalent to @(subject,body)
):
@!(title,body) hello world
All-field search operator:
@* hello
"hello world"
The phrase operator requires the words to be next to each other.
The phrase search operator may include a match any term
modifier. Terms within the phrase operator are position significant. When the 'match any term' modifier is implemented, the position of the subsequent terms from that phrase query will be shifted. Therefore, 'match any' has no impact on search performance.
"exact * phrase * * for terms"
"hello world"~10
Proximity distance is specified in words, adjusted for word count, and applies to all words within quotes. For instance, "cat dog mouse"~5
query means that there must be less than 8-word span which contains all 3 words, ie. CAT aaa bbb ccc DOG eee fff MOUSE
document will not match this query, because this span is exactly 8 words long.
"the world is a wonderful place"/3
Quorum matching operator introduces a kind of fuzzy matching. It will only match those documents that pass a given threshold of given words. The example above ("the world is a wonderful place"/3
) will match all documents that have at least 3 of the 6 specified words. Operator is limited to 255 keywords. Instead of an absolute number, you can also specify a number between 0.0 and 1.0 (standing for 0% and 100%), and Manticore will match only documents with at least the specified percentage of given words. The same example above could also have been written "the world is a wonderful place"/0.5
and it would match documents with at least 50% of the 6 words.
aaa << bbb << ccc
Strict order operator (aka operator "before") will match the document only if its argument keywords occur in the document exactly in the query order. For instance, black << cat
query (without quotes) will match the document "black and white cat" but not the "that cat was black" document. Order operator has the lowest priority. It can be applied both to just keywords and more complex expressions, ie. this is a valid query:
(bag of words) << "exact phrase" << red|green|blue
raining =cats and =dogs
="exact phrase"
Exact form keyword modifier will match the document only if the keyword occurred in exactly the specified form. The default behaviour is to match the document if the stemmed/lemmatized keyword matches. For instance, "runs" query will match both the document that contains "runs" and the document that contains "running", because both forms stem to just "run" while =runs
query will only match the first document. Exact form operator requires index_exact_words option to be enabled.
Another use case is to avoid expanding a keyword to its *keyword*
form. I.e. with index_exact_words=1
+ expand_keywords=1/star
bcd
will find a document containing abcde
, but =bcd
will not.
This is a modifier that affects the keyword and thus can be used within operators such as phrase, proximity, and quorum operators. It is possible to apply an exact form modifier to the phrase operator. In this case it internally adds the exact form modifier to all terms in the phrase.
nation* *nation* *national
Requires min_infix_len for prefix (expansion in trail) and/or sufix (expansion in head). If only prefixing is wanted, min_prefix_len can be used instead.
The search will try to find all the expansions of the wildcarded tokens and each expansion is recorded as a matched hit. The number of expansions for a token can be controlled with expansion_limit table setting. Wildcarded tokens can have a big impact on the query search time, especially when tokens have short length. In such cases is desired to use the expansion limit.
The wildcard operator can be automatically applied if expand_keywords table setting is used.
In addition, the following inline wildcard operators are supported:
?
can match any(one) character:t?st
will matchtest
, but notteast
%
can match zero or one character :tes%
will matchtes
ortest
, but nottesting
The inline operators require dict=keywords
and infixing enabled.
^hello world$
Field-start and field-end keyword modifiers will make the keyword match only if it occurred at the very start or the very end of a fulltext field, respectively. For instance, the query "^hello world$"
(with quotes and thus combining phrase operator and start/end modifiers) will only match documents that contain at least one field that has exactly these two keywords.
boosted^1.234 boostedfieldend$^1.234
The boost modifier increases the word IDF score by the specified factor in ranking scores that use IDF in their formula. It does not affect the matching in any way.
hello NEAR/3 world NEAR/4 "my test"
Operator NEAR
is a generalized version of the proximity operator. The syntax is NEAR/N
, it is case-sensitive, and no spaces are allowed between the NEAR
keywords, the slash sign, and the distance value.
The original proximity operator only works on sets of keywords. NEAR
is more generic and can accept arbitrary subexpressions as its two arguments, matching the document when both subexpressions are found within N words of each other, no matter in which order. NEAR
is left associative and has the same (lowest) precedence as BEFORE.
You should also note how one NEAR/7 two NEAR/7 three
is not really equivalent to "one two three"~7
. The difference here is that the proximity operator allows for up to 6 non-matching words between all the 3 matching words, but the version with NEAR
is less restrictive: it would allow for up to 6 words between one
and two
and then for up to 6 more between that two-word matching and three
.
Church NOTNEAR/3 street
Operator NOTNEAR
is a negative assertion. It matches the document when left argument exists and either there is no right argument in document or right argument is distance away from left matched argument's end. The distance is specified in words. The syntax is NOTNEAR/N
, it is case-sensitive, and no spaces are allowed between the NOTNEAR
keyword, the slash sign, and the distance value. Both arguments of this operator might be terms or any operators or group of operators.
all SENTENCE words SENTENCE "in one sentence"
"Bill Gates" PARAGRAPH "Steve Jobs"
SENTENCE
and PARAGRAPH
operators matches the document when both its arguments are within the same sentence or the same paragraph of text, respectively. The arguments can be either keywords, or phrases, or the instances of the same operator.
The order of the arguments within the sentence or paragraph does not matter. These operators only work on tables built with index_sp (sentence and paragraph indexing feature) enabled, and revert to a mere AND otherwise. Refer to the index_sp directive documentation for the notes on what's considered a sentence and a paragraph.
ZONE:(h3,h4)
only in these titles
ZONE limit
operator is quite similar to field limit operator, but restricts matching to a given in-field zone or a list of zones. Note that the subsequent subexpressions are not required to match in a single contiguous span of a given zone, and may match in multiple spans. For instance, (ZONE:th hello world)
query will match this example document:
<th>Table 1. Local awareness of Hello Kitty brand.</th>
.. some table data goes here ..
<th>Table 2. World-wide brand awareness.</th>
ZONE
operator affects the query until the next field or ZONE
limit operator, or the closing parenthesis. It only works on the tables built with zones support (see index_zones) and will be ignored otherwise.
ZONESPAN:(h2)
only in a (single) title
ZONESPAN
limit operator is similar to the ZONE
operator, but requires the match to occur in a single contiguous span. In the example above, ZONESPAN:th hello world
would not match the document, since "hello" and "world" do not occur within the same span.
As some characters are used as operators in the query string, they should be escaped to avoid query errors or unwanted matching conditions.
The following characters should be escaped using backslash (\
):
! " $ ' ( ) - / < @ \ ^ | ~
Single quote (') can be escaped using one backslash:
SELECT * FROM your_index WHERE MATCH('l\'italiano');
The rest of the characters in the above list are operators or query constructs. In order to treat them as simple characters, the engine has to see them with a preceding escape character. The backslash must also be escaped itself, resulting in 2 backslahes:
SELECT * FROM your_index WHERE MATCH('r\\&b | \\(official video\\)');
If we want to use backslash as character, we need to escape both the backslash as character and backslash as the escape operator, resulting in 4 backslashes used:
SELECT * FROM your_index WHERE MATCH('\\\\ABC');
MySQL drivers offer escaping functions (e.g., mysqli_real_escape_string
in PHP or conn.escape_string
in Python), but they only escape certain characters.
You will still need to add escaping for the characters from the above list that are not escaped by the respective functions.
Since these functions will escape backslash for you, you only need to add one backslash.
This also applies for the drivers that support (client-side) prepared statements. For example for PHP PDO prepared statements, you need to add a backslash for $
character:
$statement = $ln_sph->prepare( "SELECT * FROM index WHERE MATCH(:match)");
$match = '\$manticore';
$statement->bindParam(':match',$match,PDO::PARAM_STR);
$results = $statement->execute();
It will make the final query SELECT * FROM index WHERE MATCH('\\$manticore');
The same rules for SQL protocol apply with the exception that for JSON the double quote must be escaped with a single backslash, while the rest of the characters must be double escaped.
If using JSON libraries/functions that convert data structures to JSON strings the double quote and single backslash are escaped automatically by these functions and must not be explicitly escaped.
The new official clients (which use HTTP as protocol) are using under the hood common JSON libraries/functions available on the respective programming language. Same rules of escaping as above are applied.
Asterisk (*
) is a special character that can have two functionalities:
- as wildcarding prefix/suffix expander
- and as any term modifier inside a phrase search.
Unlike other special characters that are operators, the asterisk cannot be escaped when it's in a position to offer one of it's functionalities.
In non-wildcard queries, the asterisk doesn't require escaping, regardless if it's in the charset_table
or not.
In wildcard queries, asterisk in the middle of a word doesn't require escaping. As a wildcard operator (either at start or end of the word), the asterisk will always be interpreted as the wildcard operator even if escaping is applied.
To escape special characters in json nodes use a backtick. For example:
MySQL [(none)]> select * from t where json.`a=b`=234;
+---------------------+-------------+------+
| id | json | text |
+---------------------+-------------+------+
| 8215557549554925578 | {"a=b":234} | |
+---------------------+-------------+------+
MySQL [(none)]> select * from t where json.`a:b`=123;
+---------------------+-------------+------+
| id | json | text |
+---------------------+-------------+------+
| 8215557549554925577 | {"a:b":123} | |
+---------------------+-------------+------+