Can a table have multiple primary keys?

Question

SQL

Hello colleagues!
Recently I read somewhere that there can be only one primary key. This is true?
Many thanks in advance to everyone who helps

Answer 1

There can only be one primary key.
BUT
Primary key can be on multiple fields. It can sometimes be misleading that there are more than one, but that's not the case. He is always alone.

Answer 2

But if you want, you can make the primary key composite

Answer 3

there can be only one primary key. This is true?

The other will no longer be the first, only the second, and so on.

Answer 4

There is only one primary key. There can be many indexes.