make the BaseQueryBuilder interface implement Clonable

[dnavre]

Because of this interface not implementing Clonable it's impossible to prepare and reuse parts of the query like this:

BoolQueryBuilder queryPart1 = boolQuery()
for(int i = 0; i < arr.size(); i++) {
    queryPart1.must(....);
}

BoolQueryBuilder mainQuery= boolQuery()
    .should(
        queryPart1
        .must(...)
    )
    .should(
        queryPart1
        .sould(...)
   );

I'm forced to create a new bool query at each point of reuse or externalize the creation of queryPart1 to a separate method and call it whenever i'm in need of that query part

[kimchy]

You can safely reuse queryPart1 (in your code) in several places. Did you run into problems with it?

[dnavre]

not exactly :) sorry, I was not clear enough.
What i mean is this: let's suppose i have imaginary conditions condition1, condition2 and condition3. and i need to find all rows satisfying query: (condition1 && condition 2) || (condition 1 and condition3). This is just an example, in real life the query i have is pretty damned complex and i need to reuse some of it's conditions in many places. So what happens when i use this code:

BoolQueryBuilder queryPart1 = boolQuery()
for(int i = 0; i < arr.size(); i++) {
    queryPart1.must(....); // building up condition1
}

BoolQueryBuilder mainQuery= boolQuery()
    .should(
        queryPart1 // reusing condition1
        .must(...) // adding condition2
    )
    .should(
        queryPart1 // reusing condition1
        .sould(...) // adding condition3
   );

in the end I'm ending up with this query: (condition1 && condition2) || (condition1 && condition2 && condition3)

what i'd like to be able to do is:

// building condition1
BoolQueryBuilder queryPart1 = boolQuery()
for(int i = 0; i < arr.size(); i++) {
    queryPart1.must(....);
}

BoolQueryBuilder mainQuery= boolQuery()
    .should(
        queryPart1.clone() // reusing condition1
        .must(...) // adding condition2
    )
    .should(
        queryPart1.clone() // reusing condition1
        .sould(...) // adding condition3
   );

this way i'm actually able to reuse the condition throughout the query.

[dnavre]

If you're okay with it I can even try to implement this functionality myself and then do a pull request to you :)

[kimchy]

I still don't understand why you would need it. You mean be able to clone a query, and then modify it? The problem with supporting clone is the semantics for more complex query builders, one that wrap a filter or another query.

[dnavre]

sorry for the late reply.
I'd like to be able to clone the queries so i would be able to reuse a single query several times with different modifications.

lets suppose i have a boolQuery which i wrote and assigned to myBoolQuery var. I'm going to use it in several places in my final query. The first time i use it i just need to boost it, the second time i have an additional condition and the third time i have another condition. so the final result should look something like this:

boolQuery()
.should(myBoolQuery.boost(10F))
.should(myBoolQuery.must(/*blah */))
.should(myBoolQuery.must(/*another blah */);

This looks like what i'd really like to do but in reality it is not cause each time i call some method on myBoolQuery object it's changing the state of the object. What i'm ending with when using this query is the following conditional statement:

myPreparedCondition.boost()
|| (myPreparedCondition.boost() && must(/*blah*/))
|| (myPreparedCondition.boost() && must(/*blah*/) && must(/*another blah*/))

to get the query I originally wanted i need to wrap my prepared query in an additional bool query like this:

boolQuery()
.should(boolQuery().must(myBoolQuery).boost(10F))
.should(boolQuery().must(myBoolQuery).must(/*blah */))
.should(boolQuery().must(myBoolQuery).must(/*another blah */);

which in my opinion makes the code less readable and more cumbersome.

If the queries were clonable i would be able to write the query i originally wanted to have this way:

boolQuery()
.should(myBoolQuery.clone().boost(10F))
.should(myBoolQuery.clone().must(/*blah */))
.should(myBoolQuery.clone().must(/*another blah */);

another option to do this same thing is by making so that each query modifying method would not change the state of the existing query object but rather return a new query object with the modification inside of it. But I think this will be a damn lot harder to implement and I'm not even sure if this is something worth doing at all.

[alex-lx]

hi all, does this feature getting supported now? it seems muBollQuery is not clonable on version 2.4.0.

[Hronom]

Hello from 2020, this highly needed feature not available yet for reasons of "some semantic issues". But Solr have it SolrQuery.getCopy() and do deep copy.

Use case:
Imagine you write multi-query request and you have some common parts for each query. You want to re-use them, but not able to clone/copy the objects with deep copy. https://discuss.elastic.co/t/how-to-make-a-deepcopy-boolquerybuilder/211411/4

It's sad situation for me, since I understand that this will be never implemented here, even if it will be implemented now, I need this feature yesterday.

I hope developers of OpenSearch will be more friendly in the upcoming releases and will add such must have feature...