elasticsearch_dsl/search/queries/term_level/
exists_query.rs

1use crate::search::*;
2use crate::util::*;
3
4/// Returns documents that contain an indexed value for a field.
5///
6/// An indexed value may not exist for a document’s field due to a variety of reasons:
7///
8/// - The field in the source JSON is `null` or `[]`
9/// - The field has `"index" : false` set in the mapping
10/// - The length of the field value exceeded an `ignore_above` setting in the mapping
11/// - The field value was malformed and `ignore_malformed` was defined in the mapping
12///
13/// To create exists query:
14/// ```
15/// # use elasticsearch_dsl::queries::*;
16/// # use elasticsearch_dsl::queries::params::*;
17/// # let query =
18/// Query::exists("test");
19/// ```
20/// <https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-exists-query.html>
21#[derive(Debug, Clone, PartialEq, Serialize)]
22#[serde(remote = "Self")]
23pub struct ExistsQuery {
24    field: String,
25
26    #[serde(skip_serializing_if = "ShouldSkip::should_skip")]
27    boost: Option<f32>,
28
29    #[serde(skip_serializing_if = "ShouldSkip::should_skip")]
30    _name: Option<String>,
31}
32
33impl Query {
34    /// Creates an instance of [`ExistsQuery`]
35    ///
36    /// - `field` - Name of the field you wish to search.
37    ///   While a field is deemed non-existent if the JSON value is `null` or `[]`,
38    ///   these values will indicate the field does exist:
39    ///   - Empty strings, such as `""` or `"-"`
40    ///   - Arrays containing `null` and another value, such as `[null, "foo"]`
41    ///   - A custom [`null-value`](https://www.elastic.co/guide/en/elasticsearch/reference/current/null-value.html), defined in field mapping
42    pub fn exists<T>(field: T) -> ExistsQuery
43    where
44        T: ToString,
45    {
46        ExistsQuery {
47            field: field.to_string(),
48            boost: None,
49            _name: None,
50        }
51    }
52}
53
54impl ExistsQuery {
55    add_boost_and_name!();
56}
57
58impl ShouldSkip for ExistsQuery {}
59
60serialize_with_root!("exists": ExistsQuery);
61
62#[cfg(test)]
63mod tests {
64    use super::*;
65
66    #[test]
67    fn serialization() {
68        assert_serialize_query(
69            Query::exists("test"),
70            json!({
71                "exists": {
72                    "field": "test"
73                }
74            }),
75        );
76
77        assert_serialize_query(
78            Query::exists("test").boost(2).name("test"),
79            json!({
80                "exists": {
81                    "field": "test",
82                    "boost": 2.0,
83                    "_name": "test"
84                }
85            }),
86        );
87    }
88}