from the output of your first query, say you have ItemID in the results.
then in your second query, in the Dynamic Input tool, you may have something like this:
WHERE
ItemID in ('REPLACE')
go to the Dynamic Input tool configuration with the SQL, change to Modify SQL query. then use the Add dropdown, and you'll likely want "SQL: Update a WHERE clause", and hopefully you'll see "ItemID in ('REPLACE')" already there in the dropdown for you, select it and select which field streaming in has the ItemID. if you DON'T see your where clause in the dropdown, it's probably got another function on it (like trim(ItemID) in 'REPLACE') and in that case you can just type/paste it in instead of using the dropdown. I'd recommend enabling "Group Replacement Value for SQL IN Clause" since it sounds like you'll have a list of values passing through here. It will run the SQL in batches, replacing that IN clause in however many batches it takes to cycle through your list of values, subject to the Character Limit for IN Clause. That defaults to 1000 - note it's a CHARACTER limit, not an item limit. If the ItemID is 7 digits long, then account for the ' and , between them you'll have 10 characters for each ItemID in the list. So the default of 1000 characters would run the query in batches, with 100 ItemIDs at a time (1000/10). You can alter that 1000 character limit default if you want, but you'll need consider your query in how increasing or decreasing it might improve performance.
