Is the text provided to a wildcard query analyzed? - elasticsearch

I plan to use wildcard queries on analyzed text fields using asciifolding (to get rid of french accents) and lowercase.
My first tests show e.g.
matches for "wildcard": { "ar_titre.raw": { "value": "nomme*" } } but no matches for "wildcard": { "ar_titre.raw": { "value": "nommé*" } }
Does that mean that when using wildcard (or prefix) queries, the text provided to "value" is not analyzed ? Or Is that a bug ?

wildcard queries are term-level queries.
As explained in the official documentation, the wildcard expression is not analyzed:
Matches documents that have fields matching a wildcard expression (not analyzed).

Related

Elatisearch match_phrase_prefix query, with exact prefix match

I have a match_phrase_prefix query, which works as expected. But when the users passes any special characters at the end of the keyword, ES ignores these characters, and still returns the result.
query{ match_phrase_prefix:{ content: { query: searchTerm } } }
I am using this query to search for prefix. If i pass a term like overflow####!! ES is returning me all the results with the word overflow in it. But instead i want to make an exact prefix match, where the special characters are not ignored. The search term could be of multiple words as well stack overflow search.
How could i make ES search of prefix_match without ignoring the special_chars.
You can use keyword analyzer when defining your query.
{
"query": {
"match_phrase_prefix": {
"content": {
"query": "overflow####!!",
"analyzer": "keyword"
}
}
}
}

How to filter multiple characters in Elasticsearch

Is there a way how to filter multiple characters during analyzing in ElastisSearch? We would like to setup it so if user searches 'botled' then he get the documents that include 'bottled' or 'botttled', etc., i.e no matter double, tripple letters.
I have looking for solution in token filters https://www.elastic.co/guide/en/elasticsearch/reference/current/analysis-tokenfilters.html, but it seems that none of them matches our requirements.
by default elasticsearch text field is tokenized based on whitespace, i.e. only words are indexed and are searchable.
would regex search work for you?
GET /_search
{
"query": {
"regexp": {
"user": {
"value": "b+o+t+t+l+e+d+"
}
}
}
}
b+ --> one or more occurrence of b

In Elasticsearch match query how to deal with slash

I have a match query searching for a type of doc:
{
"query": {
"bool": {
"should": {
"match": {
"ph1_enc": "EAAQnb1kMr/e2/ADqo"
}
}
}
}
}
"EAAQnb1kMr/e2/ADqo" is the string i'm trying to match, however in the search results I can see multiple records with substring "/e2/" are also returned.
Looks like "/e2/" is indexed separately, so that this could happen.I thought the match query is to do full-text match... Is it because I missed something when creating the template? Any idea?
Add-on instead of reindex, how to modify the query to match the exact value in the query?
Which analyzer do you set in the mapping to index your data?
If you are using the default one (standard analyzer), then according to the documentation, this uses the default tokenizer that seems to split also the text by slash ('/'). The documentation redirects here for more information about the tokenizer.
So, that will index the following words 'EAAQnb1kMr', 'e2', and 'ADqo'. Accordingly, your query value will also been analyzed the same way the field was indexed. That is why documents with 'e2' are also being returned.
If you don't need to tokenize the 'ph1_enc' field, you can just set its type in the mapping as 'keyword'.
"properties": {
"ph1_enc": {
"type": "keyword"
}
}
That will not analyze the field and it will match exactly while you query.
I hope that it helps.

Elasticsearch wildcard query not honoring the analyzer of the field

I have a field named "tag" which is analyzed(default behavior) in elasticsearch. The "tag" field can have a single word or a comma separated string to store multiple tags. For eg. "Festive, Fast, Feast".
Now for example if a tag is "Festive", before indexing I am converting it to small case(to ignore case sensitivity) and indexing it as "festive".
Now if I search using a match query with all caps letters as mentioned below I get results fine(as expected).
{
"query": {
"match": {
"tag": "FESTIVE"
}
}
}
But if I do a wildcard query as mentioned below I don't get results :(
{
"query": {
"wildcard": {
"tag": {
"value": "F*"
}
}
}
}
If I change the value field in wildcard search to "f*" instead of "F*" then I get results.
Does anyone have any clue why is wildcard query behaving case sensitive?
Wildcard queries, fall under term level queries and hence not analyzed. From the Docs
Matches documents that have fields matching a wildcard expression (not
analyzed)
You will get expected results with query string query, it will lowercase the terms because by default as lowercase_expanded_terms is true. Try this
GET your_index/_search
{
"query": {
"query_string": {
"default_field": "tag",
"query": "F*"
}
}
}
Hope this helps!

How to deal with punctuation in an ElasticSearch field

I have a field in a document stored in Elastic Search, which I want to be analyzed as a full text field. In one case, it contains a value for the name field like this:
A&B Corp
I want to be able to search the documents for an auto-complete widget, using a query like this (suppose the user typed A&B into the autocomplete field). The intention is to match documents that contain the any terms with the typed prefix.
{ "query": {
"filtered": {
"query": {
"query_string": {
"query": "A&B*",
"fields": [
"firstName",
"lastName",
"name",
"key",
"email"
]
}
},
"filter": {
"terms": {
"environmentId": [
"foo"
]
}
}
}
}
}
```
My mapping for the name field looks like this:
"name": {
"type": "string"
},
But, I get no results. The query structure works for documents that don't have & in the field, so I'm pretty sure that is part of the problem.
But, I'm not sure how to deal with this. I am pretty sure I still want to analyze the field for full text search.
In addition, if I add a space before the * in the query (ie, "query": "A&B *",) then I get results including A&B, so I don't think it is just discarding the ampersand and treating the A and B as separate terms.
Should I change my mapping? The query?
The Query_string query has a set of reserved characters that needs to be escaped.
query_string : Read the reserved characters section
So to search for
'A&B' (or) 'A&B Corp' (or) 'A&B....'
Your query must be "A&B\\*" such that the query_string parser treats
it as a * wildcard operator.
While currently your query is searching for exact match of
"A&B*" it expects asterik to be part of your data.
And when you search "A&B *" the whitespace is a reserved
character so its
now searching for "A&B" (or) "*" and hence you get a match in this
case.

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