select every other row in MySQL without depending on any ID?

Question

Considering following table that doesn\'t have any primary key, can I select every other row?

col1      col2
 2         a
 1         b
 3         c
 12               


        

Answer 1

yes possible using temp variable

Example :

set @a := 0;
select * from car_m_city  WHERE mod((@a:=@a+1), 2) = 1

Explanation :

here in sql we declare @a( set @a := 0;) temp variable.(@a:=@a+1) now @a increment by 1.jsut like simple way to check odd or even

mod((@a:=@a+1), 2) = 1 for odd data

mod((@a:=@a+1), 2) = 0 for even data