Iam Srinivas working as a programmer.I want approach regarding customizing Query for any database.I will clearly explain...

Sometimes we don't which database the client is using,he may use SQLServer,MYSQL,MS Access,Oracle.So i want to customize my query for all these databases i.e The Query i have written should insert or retrieve data from any of these databases.

So what is the approach i should follow ,is there any query builder to generalise Queries.Plz give me answers quickly because i got very less time and i need to start my project as soon as i get the answer for this.

Sreenivasu Puppala