eq_join like functionality on a single object

Question

I have 2 tables child and parent:

child
    {id:1, parent_id: 10, name:"blah" ...}

parent
    {id:10, name: "parent blah" ....}

I know the id of the child object and want to query the child object joined with the parent object.

Is there a way i can do the equivalent of :

r.table('child').get(10).eq_join('parent_id', r.table('parent'))

eq_joins work great on the results of a filter operation since it returns a sequence. I want to perform a similar operation when i use get

so an eq_join of the form:

r.table('child').filter({'id': 1}).eq_join('parent_id', r.table('parent'))

gives me records

{left: {id: 10, parent_id:1, ...},
right: {id:1, ....}}

which works great for a sequence.

I want to carry out the same operations in a case where I use a get instead of filter.

Answer 1

You can do something like that (in Python)

r.table('child').get(10).merge(lambda child:
    {
        'parent': r.table('parents').get(child['parent_id'])
    }
)

If you want exactly the same output as with eq_join, you can do

r.expr([r.table('child').get(10)]).eq_join('parent_id', r.table('parent'))