MySQL PLSQL Demo - 005.IF THEN ELSEIF THEN ELSE END IF

drop procedure if exists p_hello_world;

create procedure p_hello_world(in v_id int)
begin
    if (v_id > 0) then
        select '> 0';
    elseif (v_id = 0) then
        select '= 0';
    else
        select '< 0';
    end if;
end;

call p_hello_world(-9);