I’m building a React front end that has a sidebar with checkboxes that filter down a base query. However, this is starting to get messy and i’m wondering what the best way to accomplish this is.
I’ve also noticed Ecto now has a dynamic function but i’m unsure how I can use this (if applicable at all).
Previously i’ve used reduce to compose the base query with additional where clauses but now I also need an and clause and am getting stuck. I’ve pasted in a cleaned up example below
This is the hard coded query I want to end up composing:
base_query = from i in Interest,
where: i.interest_list_id == ^interest_list_id,
where: i.is_complete == true
and (i.household_lives_in_foo == true or i.household_works_in_foo == true)
I’m unsure how to go about this with both my composed code below that’s using the field function to generate dynamic where clauses. What I want to do is:
and(acc, [r], [field(r, ^field1), field(r, ^field2)])
but that doesn’t work. Full example:
# compose a more complex query based on data [{"age", %{eq: 21}}, {...}]
#
def fetch_completed_interests(interest_list_id, filter_params) do
base_query = from i in Interest,
where: i.interest_list_id == ^interest_list_id,
where: i.is_complete == true
# this is the query I need to make dynamic
query_with_filters =
Enum.reduce(filter_params, base_query, fn {field, selector}, acc ->
case {field, selector} do
{_field , %{eq: value}} ->
where(acc, [r], field(r, ^field) == ^value)
{_field , %{lt: value}} ->
where(acc, [r], field(r, ^field) < ^value)
{_field , %{or_group_true: value}} ->
field1 = "household_lives_in_foo"
field2 = "household_works_in_foo"
# this is what I want to do but doesnt work (similar to where/3 above)
# from:
# and(acc, [r], [field(r, ^field1), field(r, ^field2)])
# to this:
# and (r.household_lives_in_foo == true or r.household_works_in_foo == true)
{_field, %{}} -> # this can match *any* map not just an empty one
base_query
end
end)
{:ok, Repo.all(query_with_filters)}
end
