You have several options.
You can us Lua scripts (available in StrokeIt Pro) to store and insert your snippets through the clipboard. Or, if you are into SQL you can use Auto Hotkey to store and insert your snippets directly and invoke its scripts from StrokeIt or (which is better) with a user defined hotkey. IMHO it's faster than switching back and forth between mouse and keyboard. But if you are really, really into SQL I'd suggest you to try SQL Assistant which is quite powerful (though not at all a cheap) state-of-the-art tool for SQL.