Ok, lets start with Germany.
Basically some knives are illegal, some restricted for carry and the rest is Ok.
Firstly there a outlawed knives: butterfly or bali song, gravity operated knives and knives with their blade perpendicular to the hilt (push dagger style). You are not allowed to own them. Don´t even bring them.
You can´t carry accessibly fighting knives (double edged or advertised as such), fixed blade knives with more than 12 cm blade length(that is a little less than 5" and yes in some regions that 1/4" might matter), folding knives that can be opened and locked one handed. Size does not matter here, switchblades are included. This the opinion of the federal police (BKA) some knife enthusiasts may not share this opinion. If push comes to shove, judges are going to share the opinion of the federal police. If you carry one of those knivs, you need a reasonable cause. If your German is not fluent, don´t carry. You might be in for some unpleasant experience. However you can have them in a locked container.
Fixed blades that do not fall in one of the above categories, non-locking folders and locking folders that need both hands for opening are Ok for EDC.
Now for some policy:
If you are ask by a LEO why you carry a knife never ever mention selfdefence. The term "brotzeit" would describe a reasonable and accepted cause.