Using “Select All” into a dynamic query

After changing a report Select statement into dynamic-sql I found “Select All” no longer worked for my “Customers” parameter.

To fix this, in Dataset/Properties/Parameters I changed the Parameter Value to

=join(Parameters!customer.Value,"','")

To translate … after the “.Value” there is … comma, double-quote, single-quote, comma, single-quote, double-quote, close-bracket. So that in the query each value would be surrounded by its own single quotes
simples 🙂