How to filter relationships in Donis?

Question

I pass this query:

const filter = request.input('filter')
const queryBookQuestions =  BookUnitQuestion
                                    .query()
                                    .with('book_unit')
                                    .with('user')
                                    .with('book', (builder) => {
                                        builder.where('id', request.params.id)
                                    })

In this query I return all the books of a book unit with the object book_unit related to it, the user and bring only the questions of the book that receive as parameter (book.params.id)

Now I need to filter the questions by units. I have this filter that works correctly looking for the description of the question:

if(filter){
            if(filter.search("description") !== -1){
                let description = filter.match(/(?<=description~contains~').*?(?=')/)
                queryBookQuestions.where('description', 'ilike', '%'+description[0]+'%')
            }

This filter works well because I believe it is applied directly in the model BookUnitQuestion. But now, I need to filter the Unit, which is a relationship, that is, I need to return the questions that have only in the unit that I filter. I tried something like:

if(filter.search("unit") !== -1){
                let unit = request.input('filter').match(/(?<=unit~contains~').*?(?=')/)

                queryBookQuestions.where('book_unit.unit', unit[0])}

        }

But this way I get:

select Count(*) as "total" from "book_unit_question" Where "book_unit"." Unit" = $1 - Missing FROM-clause entry for table "book_unit"

Answer 1

It seems a matter of the moment of processing the arguments. Try changing the Where to whereRaw. You must solve.