How to notify user if argument is empty in discord py command?

Question

Python

Good day, here is an example code:

@commands.command(aliases=['ник', 'авторизация', 'ybr'])
async def chnick(self, ctx, nick, serv):
    await ctx.send(f"Пользователь: {nick}-{serv}")

How to track an empty argument and write a warning (ex. )await ctx.send("Вы не указали ник")

Answer 1

Well, as if everything is written the same.
SQL tells you "there is no column named categories in the msg table "
Why not? And because in the CREATE TABLE code you named it category
PS In general, it looks like not a very good code.
It seems to me a) you should not use sqlite b) you should not create tables in the model code.