STAR Selection: Result predictable order of columns

[pgollangi]

When all fields of Firestore documents selected using STAR selection (select * from users), the order of columns resulted is not always same.
This is because when STAR selected, FireQL don't explicitly request column selections to get all fields of Firestore collection and uses data returned by Firestore.DocumentSnapshot which is a map field and value pair where order of key is not always same.

One way to return the same columns always would be by sorting columns (map keys) returned by DocumentSnapshot.Data

[rafiramadhana]

does it mean we need to sort the columns (selectedColumns) before exiting this if-else statement select.go#L109?

if starIdx != -1 {
    ...
        }
        starIdx++
    }
    // TODO: Sort selectedColumns before exiting this if-else statement
}

[pgollangi]

Hi @rafiramadhana thanks a lot for your interest in this project.

Sorting selectedColumns would possibly change the position of other selected columns along with *. For example select user_id, *, account_id from users should list user_id first and account_id last in resulted columns and remaining all columns in order in place of *.

You could possible collect all fields from data and sort then add it to selectedColumns rather than adding it on-the-fly.

[rafiramadhana]

@pgollangi i see, to spawn a mocked firestore in local, is it enough by doing these steps?

• Run gcloud beta emulators (ref: select/select_test.go)
• Populate the collection using data/users.json

btw is there any UI/CLI app to interact with the mocked firestore? like for seeing data, updating data, adding collection, etc

[pgollangi]

@rafiramadhana yes thats right. I generally follow programatical way of manage firestore data, I found it easy. however there are many open-source and commercial tools to connect firestore.