When comparing A5:SQL Mk-2 vs QueryPie, the Slant community recommends QueryPie for most people. In the question“What are the best SQL Clients for Windows?” QueryPie is ranked 3rd while A5:SQL Mk-2 is ranked 15th.
Ranked in these QuestionsQuestion Ranking
Pro ER diagrams
Supports two-way Entity Relationship diagrams.
Pro Excel support
Support for Excel input and output.
Can be made portable by simply creating a folder "Portable" in the app folder.
Pro Clean and pretty UI/UX
The default color is dark and comfortable for the eyes.
Pro Multiple Query Tabs!
The multi-tab and multi-SQL-runs are great. It's always good to be able to compare results in one window instead of having to go through and re-run stuff.
Pro Fast Auto-complete
Pro Multiple Databases
They only support 2 at the moment (MySQL and MariaDB) but their social site says they'll be updating with more DBMSes in the near future which is pretty nice because I hate learning new GUIs~
Not sure about Linux but it works on Windows and Mac just fine!
The website is mostly in Japanese.
Con Requires creating an account
Requiring an account is rare on SQL IDEs...