How do I SELECT data from child table in PostgreSQL?

Question

In PostgreSQL 9.4, how do I retrieve json object like this:

parentTableFirstProp: \'string\',
parentToChildReference: [
    {childTableFirstProp: \'another strin         


        

Answer 1

A new feature in PostgreSQL 9.2 but I didn't test the query:

I follow the tutorial from here.

select row_to_json(t)
from (
select ParentTable.parentTableFirstProp, (
select array_to_json(array_agg(row_to_json(child)))
  from (
    select childTableFirstProp
    from ChildTable
    where ChildTable.id=ParentTable.parentToChildReference
  ) child

  ) as parentToChildReference
from ParentTable
) t