How do I pass parameter to view?

[amitava82]

I have a view that does custom aggregation on a table. However, I need to do the aggregation on a particular date range. How do I pass the start and end date parameter dynamically when doing graphql query? For example:

CREATE
OR REPLACE VIEW "public"."v_metrics" AS
count(*) AS total
from events
WHERE
    start_at >= 'start_date' AND start_at < 'end_date' 
GROUP BY
  user_id

And then from graphql query I should be able to do something like.

query {
  v_metrics(where: {start_at: {_eq: "2022-01-01"}, start_at: {_eq: "2022-02-01"}})
}

[SamirTalwar]

It depends how tied you are to the view. Views don't take parameters; you'll want a function for that.

If you don't really need the view, you could write the query directly; it'd look something like this:

query {
  events_aggregate(
    where: {
      _and: [
        {start_at: {_gte: "2022-01-01"}},
        {start_at: {_lt: "2022-02-01"}}
      ]
    }
  ) {
    aggregate {
      count
    }
  }
}

This uses the comparison operators _gte for >= and _lt for <.

If you really this to be encoded in the database itself, I recommend using a function, and then calling that function from Hasura, or using a native query.

[amitava82]

Understood, yes I do need the view since the query is complex that cannot be done with direct query (above example was a simplified). I'll look at the docs and figure out alternative. At least I know view cannot take parameters.