ElasticSearch 'range' query returns inappropriate results - elasticsearch

Question

Lets take this query:
{
"timeout": 10000,
"from": 0,
"size": 21,
"sort": [
{
"view_avg": {
"order": "desc"
}
}
],
"query": {
"bool": {
"must": [
{
"range": {
"price": {
"from": 10,
"to": 20
}
}
},
{
"terms": {
"category_ids": [
16405
]
}
}
]
}
}
}
This query on data set that I am running on, should return no results (as all prices are in 100s-1000s range). However, this query returns results, matching prices as:
"price": "1399.00"
"price": "1299.00"
"price": "1089.00"
And so on, and so forth.. Any ideas how I could modify the query, so it returns the correct results?

Answer 1

I'm 99% sure your mapping is wrong and price is declared as string. Elasticsearch is using different Lucene range queries based on the field type as you can see in their documentation. The TermRangeQuery for string type acts like your output, it uses lexicographical ordering (ie. 1100 is between 10 and 20).
To test it you can try the following mapping/search:
PUT tests/
PUT tests/test/_mapping
{
"test": {
"_source" : {"enabled" : false},
"_all" : {"enabled" : false},
"properties" : {
"num" : {
"type" : "float", // <-- HERE IT'S A FLOAT
"store" : "no",
"index" : "not_analyzed"
}
}
}
}
PUT tests/test/1
{
"test" : {
"num" : 100
}
}
POST tests/test/_search
{
"query": {
"bool": {
"must": [
{
"range": {
"num": {
"from": 10,
"to": 20
}
}
}
]
}
}
}
Result:
{
"took": 12,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 0,
"max_score": null,
"hits": []
}
}
If you delete the index and try to recreate it changing the num type to a string:
PUT tests/test/_mapping
{
"test": {
"_source" : {"enabled" : false},
"_all" : {"enabled" : false},
"properties" : {
"num" : {
"type" : "string", // <-- HERE IT'S A STRING
"store" : "no",
"index" : "not_analyzed"
}
}
}
}
You'll see a different result:
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 1,
"hits": [
{
"_index": "tests",
"_type": "test",
"_id": "1",
"_score": 1
}
]
}
}

Answer 2

price needs to be a numeric field for that must to work. If it's string it will return. Make sure the mapping is correct, if it would have been float it would have worked.
You can check the mapping of the index with GET /index_name/_mapping.
If you would have had the following (and the price is string):
"range": {
"price": {
"from": 30,
"to": 40
}
}
that shouldn't return the docs because 1 (string) is before 3 or 4 (strings), even if numerically speaking 30 is smaller than 1399.