dynamically select data with 20 input parameters

Hi Experts,

Now i have created a subscreen with more than 20 fields on it. these fields are defined by parameters, not select options. user can input any fileds for these input parameters.

So now i should write codes to select data from database according the user input. Is there any easy way for me to write it? I heard about dynamically SQLs, but i don't know how to use it.

Thanks a lot!