Filter new data before joining

When joining data from a table B to an existing table A , is it possible to apply a filter on the joined data?
Basically I want to do the following (but with a source that does not support sql query)

left join B on = A.k and B.Type=“active”

but I don’t want A to be filtered, so I can’t use the filter pane

Maybe you can set up a calculated field in the dataset that checks if type = “active” and also allows rows from table A which do not have a corresponding match in table B.
You would do the join on just = A.k, and then add this calculated field:

  ifelse( isNull({fk}) OR {Type} = "active", 1, 0)

And then use this calculated field in the filter pane to filter for value equals 1

Hi, are you doing the join for the two dataset at data prep phase? When you load the dataset, you can add filter before you join the two tables.

Create a dataset on A, without filter.
Create a dataset on B, with filter.
Create a composite dataset by A join B.

I wanted to avoid doing that to limit my number of datasets but it does work