title: Azure Data Factory get data for "For Each"component from query
body: <p>The situation is as follows: I have a table in my database that recieves about 3 million rows each day. We want to archive this table on a regular base, so that only the 8 most recents weeks are in the table. The rest of the data can be archived tot AZure Data lake.
  I allready found out how to do this by one day at a time. But now I want to run this pipeline each week for the first seven days in the table. I assume I should do this with the "For Each" component. It should itterate along the seven distinct dates that are present in the dataset I want to backup. This dataset is copied from the source table to an archive table on forehand.
  It's not difficult to get the distinct dates with a SQL query, but how to get the result of this query into an array that is used for the "For Each" component?</p>