I have a couple of feature requests that nothing else seems to be able to do:
1. Parameterised queries (ideally with an ability to customise the syntax for the placeholders - we use :param for named parameters). All of our production queries are parameterised, and it would be awesome to be able to copy and paste them into this kind of tool, and run them unmodified. Especially as they sometimes use the same parameter in multiple places, so updating them.
2. A full editor control (e.g. Code Mirror, Monaco, or Ace) for editing SQL queries. Specifically I really want multiple cursors for editing queries quickly and efficiently.