About Redash querying Mongodb


We want to implement Redash for our project. So, I wanted to know a few things.
I wanted to know if we can add custom columns in report fetched from mongodb in redash.
For example:
Name Marks Subject Grade
A 50 S1 C
B 70 S1 B
C 80 S1 A

Now, in above report, Name, Marks and Subject are the columns fetched from DB. Whereas, Grade is a custom column added whose value is dependent on the value of Marks. Can we do it in Redash?

Also, i want to know If a document has nested json, For example, Userinfo has value as
“firstname” : “Parveen”,
“lastname” : “Badoni”,
“age” : “28”

Now, if i want to show firstname only in a column, how can i do it? As i have seen that redash fetches complete value of document.


Calculated field: if MongoDB supports such queries, it should be possible in Redash.

Nested JSON: unfortunately we currently don’t support those. You will need to map the fields you need to be unnested; maybe with Aggregation Framework’s $project.