The use of `push_bind` here is strange to me. The idomatic way would be do something like:

    let mut builder = Query::select();

then you could (optionally) add clauses like so:

    builder.and_where(Expr::col("id").eq("A"))

it shouldn't matter if a where clause exists or not, the builder should figure that out for you.

If you are going to treat your QueryBuilder as glorified StringBuilder, then of course you won't see the value of a QueryBuilder.