Elasticsearch: Find all parents where all children have a property with a specific value - elasticsearch

Question

I have the current schema:
Object parent with property date and n children child
Object child contains a single property foo
I want to retrieve all parent where all child have their property foo equals to 0
I tried different approach but whatever I do, some parent are retrived while one child has the property foo at 1
Example of my query:
{
"query": {
"bool": {
"must": [
{
"range": {
"date": {
"lt": "2018-07-05T10:00:00.000Z"
}
}
},
{
"nested": {
"path": "child",
"query": {
"bool": {
"must": {
"term": {
"child.foo": 0
}
}
}
}
}
}
]
}
}
}
I tried with should, match, range... even must_not/should_not. I also tried filtering without any luck, I keep getting hits with the foo property at 1.
I also tried the aggregation path but I don't understand how to apply it to my need.
EDIT: I looked at the possible duplicate. While it did not answer my question, it put me on the right track. My issue was that I was thinking in a SQL way, with joins and such. While I should have thought in the elastic way.
Thus, what I wanted to do could not be done. What I needed was to look for parent where at least one child had the foo property at 1 or more. Then, ignore these results and take the others. Thus the answer is simple: I just add to change the must of the nested query by a must_not and that was it!

Answer 1

As I explained in the edit of my question, the answer is fairly easy once you start thinking in the right way./
{
"query": {
"bool": {
"must": [
{
"range": {
"date": {
"lt": "2018-07-05T10:00:00.000Z"
}
}
},
{
"nested": {
"path": "child",
"query": {
"bool": {
"must_not": {
"term": {
"child.foo": 0
}
}
}
}
}
}
]
}
}
}
The trick was just to set a must_not