TimoYang

Hey all again——

Why count(0) and count(1)——What does 0 and 1 mean here？And what's the MOST DIFFERENCE BETWEEN the two statements？

There is no difference.

you must see this

select count(0)  --0 means expression only
select count(1)  --1 means expression only

---both above results show output one
--becuase count function require

--as well as check this
select COUNT(*)


--this will also return value 1 becuase count function is not used in select query