There is a case_insensitive
parameter available for wildcard
query, but it was introduced in Elasticsearch 7.10.0, so you need to upgrade if you are still on 7.9.1.
If you can upgrade to 7.10.0 or higher:
Ideally, in index mapping field should use wildcard
type:
{
"mappings": {
"properties": {
"url.path": {
"type": "wildcard"
}
}
}
}
Then a wildcard
query with case insensitivity enabled will find all the variants ("download", "DOWNLOAD", "download", etc)
{
"query": {
"wildcard": {
"url.path": {
"value": "*download*",
"boost": 1,
"rewrite": "constant_score",
"case_insensitive": true
}
}
}
}
If you must remain at 7.9.1:
Define your mapping in such a way that Elasticsearch treats the field contents as lowercase. The following will mimic wildcard type (it's a keyword, so only one token) indexed as lowercase.
{
"mappings": {
"properties": {
"url": {
"type": "text",
"analyzer": "lowercase-keyword"
}
}
},
"settings": {
"analysis": {
"analyzer": {
"lowercase-keyword": {
"type": "custom",
"tokenizer": "keyword",
"filter": "lowercase"
}
}
}
}
}
The query, without the case_insensitive
parameter which is unsupported in this version:
{
"query": {
"wildcard": {
"url": {
"value": "*download*",
"boost": 1,
"rewrite": "constant_score"
}
}
}
}
Example results (note that searching for "*download*"
and "*DoWnLoAd*"
with both work in the same way):
{
"hits": {
"total": {
"value": 3,
"relation": "eq"
},
"max_score": 1.0,
"hits": {
"total": {
"value": 3,
"relation": "eq"
},
"max_score": 1.0,
"hits": [
{
"_index": "my-index",
"_type": "_doc",
"_id": "PtbQe3wByTvslqtrs7Cn",
"_score": 1.0,
"_source": {
"url": "http://example.com/download"
}
},
{
"_index": "my-index",
"_type": "_doc",
"_id": "P9bQe3wByTvslqtrvbDt",
"_score": 1.0,
"_source": {
"url": "http://example.com/Download"
}
},
{
"_index": "my-index",
"_type": "_doc",
"_id": "QNbQe3wByTvslqtrzbDw",
"_score": 1.0,
"_source": {
"url": "http://example.com/DOWNLOAD"
}
}
]
}
}