Question

I’m developing Web Service that has access to database via JDBC. I’m using DAO pattern. I’ve implemented all necessary methods: findAll, add, update, delete. But I got confused with update method. It has Object as input parameter. But how does he know which field needs to be updated. For example, I need to update field ‘name’ I use query 'update table set name='smth where id=2' but if I need to update ‘surname’?? what is the best practice to tell update method what actually to update?
thank you

Answer 1

You’ll need to change your method signature to include a Map of column names and values.

public interface FooDao<K, V> {
    // other methods here, of course.
    public void update(V target, Map<String, Object> parameters); 
}

Have a look at the Spring JDBC template for a nice example of how to design and implement such a thing.