I have given an assignment to get the feasibility for making a dll which takes some inputs such as database name(Mysql,access, sql, oracle etc.) and some more inputs to generate a query and based on that the dll should return a recordset to the application.

is it a good idea. if yes then what inputs should i consider

the dll will be generalized that is it may be used for any project so i can't make classes for the particular object like user or employee etc. hope my question is clear to you all if not then please find some time to go through the following conversation
http://forums.asp.net/t/1432123.aspx