Currently, the number of parameters that can be set for External Database Connector is fixed, even when used in the In clause.
select * from customers where country in ({Parameter1}, {Parameter2}, {Parameter3});
When using the External Database Connector, I want you to create a string variable called Parameter1 in your microflow and then be able to loop through a list of values (Parameter1 = 'Germany, France, UK, ・・・') and set the value for that single parameter.
select * from customers where country in ({Parameter1});
This allows you to specify search conditions dynamically, making it easier to implement search actions using SQL.