Hello,
I create a simple command like "select * from employee where employeeID in {?empID}
then I create a command parameter within the Modify Command window and I define it as a number datatype and I check the allow multiple values.
this is working fine.
Now I want to dynamically retrieve the values of this parameter from the database. So I modify the parameter in the field explorer. I set the parameter List of values to Dynamic and I choose the fields from the database fields: empID and empName as the description.
Now when I refresh the report I get the parameter screen twice. why is that? how can I make it popup the parameters screen only once?

I'm using CR 2008 SP2
Please help.

This is not precise. I defined the parameter within the command and then I'm editing it in the field explorer. I change it to dynamic instead of static.

The main different put the selection criteria i the SQL command (as where clause) and put in as a selection formula is performance.
when you do this in the selection formula the criteria dose not combine in the SQL. Instead it retrieve all the data from the database and then filter the data within the report. Now what will happen if you put a command like "select * from employee" and then put a selection formula emp_id = 10. It will retrieve all the Million employees and the filter it to employee number 10.
the other way to do this is to use the command with a parameter - "select * from employee where emp_id = {?param}" in the command window you can create a parameter that will show up automatically in the field explorer later.
In this case the report will retrieve only the selected employee from the database and not all the employee table.