What is the point of using a query builder if you’re only going to support a single RDBMS? Why not write straight SQL and avoid the unnecessary abstraction layer? Is the query builder really going to be easier to learn to use (particularly for non-trivial queries) than SQL?
If your DB schema is expressed as an object/class it means your IDE will have robust autocompletion. It’s just a convenience to avoid having to look up the schema for whatever tables you’re interacting with. It helps cut down on trivial bugs during the writing phase, before you even get to testing.
