How to filter query based on a field value - elasticsearch

Question

I'm working with elasticsearch Query dsl, and I can't find a way to express the following:
Return results that have the field "price" > min budget and have "price" < max Budget and have has_price=true and also return all results that have "has_price=false"
In other words, I would like to use a range filter on results only that have has_price field set to true, otherwise, on results that have has_price set to false don't take in consideration the filter
Here's the mapping:
{
"formations": {
"mappings": {
"properties": {
"code": {
"type": "text"
},
"date": {
"type": "date",
"format": "dd/MM/yyyy"
},
"description": {
"type": "text"
},
"has_price": {
"type": "boolean"
},
"place": {
"type": "text"
},
"price": {
"type": "float"
},
"title": {
"type": "text"
}
}
}
}
}

Answer 1

The following query combines the 2 scenarios as 2 should clauses in a bool-query. And as there are only should clauses, minimum_should_match will be 1, meaning that at least one should-clause has to match:
Abstract Code Snippet
GET formations/_search
{
"query": {
"bool": {
"should": [
{ <1st scenario: has_price = false> },
{ <2nd scenario> has_price = true AND price IN budget_range}
]
}
}
}
Actual Sample Code Snippets
# 1. Create the index and populate it with some sample documents
POST formations/_bulk
{"index": {"_id": 1}}
{"has_price": true, "price": 2.0}
{"index": {"_id": 2}}
{"has_price": true, "price": 3.0}
{"index": {"_id": 3}}
{"has_price": true, "price": 4.0}
{"index": {"_id": 4}}
{"has_price": false, "price": 2.0}
{"index": {"_id": 5}}
{"has_price": false, "price": 3.0}
{"index": {"_id": 6}}
{"has_price": false, "price": 4.0}
# 2. Query assuming min_budget = 2.0 and max_budget = 4.0
GET formations/_search
{
"query": {
"bool": {
"should": [
{
"bool": {
"filter": {
"term": {
"has_price": false
}
}
}
},
{
"bool": {
"filter": [
{
"term": {
"has_price": true
}
},
{
"range": {
"price": {
"gt": 2,
"lt": 4
}
}
}
]
}
}
]
}
}
}
# 3. Result Snippet (4 hits: 3 from 1st scenario & 1 from 2nd scenario)
"hits" : {
"total" : {
"value" : 4,
"relation" : "eq"
},
...
Don't forget to add the Claus "minimum_should_match": 1 to your bool-query in case you add another non-should-clause to your bool-query.
Let me know if this answers your question & solves your issue.