Is it possible to somehow count the data of a column in a table?

Question

SQL

I want to calculate on the fly, data in a table column. Basic example:
there is a user id, it is not generated by auto-increment, that is, the second record may have id = 5691234, instead of 2.
How to calculate the total value of all user ids, on the fly using only SQL?

Answer 1

How to calculate the total value of all user ids on the fly using only SQL?
SELECT SUM(id) FROM table1;