-- "foof" was a table containing 11 rows
-- You can make one using Tools | Create reference table...
-- the number of rows doesn't matter, but 10 or greater is best.

-- drop table if exists foof2;
create table foof2 (
  w double,
  x double,
  y double, 
  z double default 0
);

insert into foof2(w, x,y)
  select * from foof a, foof b, foof c;

update foof2
  set w=rand(), x= rand(), y=rand();


update foof2 
  set z = w+x*x+y*y*y;

plot correlation
  tiny filled red circle
select * from foof2;