A bool query is a query type in Elasticsearch that allows for the construction of complex search queries using Boolean logic. It combines multiple query types using Boolean operators, such as “must”, “should”, and “must_not”, to create more powerful and flexible search queries.
The bool query can be used to construct queries that require multiple conditions to be met, such as searching for documents that contain certain keywords in one field and certain dates in another field. Here’s an example of a bool query:
GET /my_index/_search
{
"query": {
"bool": {
"must": [
{ "match": { "title": "Elasticsearch" }},
{ "range": { "date": { "gte": "2022-01-01", "lte": "2022-12-31" }}}
],
"must_not": [
{ "term": { "category": "books" }}
],
"should": [
{ "match": { "author": "John" }},
{ "match": { "author": "Jane" }}
],
"minimum_should_match": 1
}
}
}
In this example, we are searching the `my_index` index for documents that meet the following conditions:
– The `title` field must contain the term “Elasticsearch”
– The `date` field must be between January 1, 2022 and December 31, 2022
– The `category` field must not contain the term “books”
– The `author` field should contain either the term “John” or the term “Jane”
The `minimum_should_match` parameter specifies that at least one of the `should` queries must match in order for the document to be considered a match.
By combining multiple query types using Boolean logic, the bool query provides a powerful and flexible way to construct complex search queries in Elasticsearch.