What is it you're trying to do? Generally, professional mics all are XLR or some variant, not 3.5mm (there are lots of reasons for this). If you're looking at a camera that only has mini input, there are lots of adapters (from beachtek to Sound Devices) that you can use to take an XLR mic into a mini jack.
In a pinch it also works to have just a XLR to miniplug cable. You need to soldier the hot lead to both L and R channels with common ground to get a mono recording on both channels. This works with any (standard) non-phantom mic. I have never had any problems with this.
Not saying that a Beachtek or similar would not give some extra confidence and convenience sometimes. I have one on my TRV900.