Even numbers (in tutorial) does not work for sqlite

[RAbraham]

Hi,
If I run this, I don't get even numbers.

%%logica Even
@Engine("sqlite");

Z(x) :- x in Range(20);

Even(x) :- Z(x), Z(x / 2);

print('Even numbers:', ', '.join(map(str, Even['col0'])))

Even numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19

This is the generated SQL:

The following query is stored at Even_sql variable.
SELECT
  x_4.value AS col0
FROM
  JSON_EACH((select json_group_array(n) from (with recursive t as(select 0 as n union all select n + 1 as n from t where n + 1 < 20) select n from t))) as x_4, JSON_EACH((select json_group_array(n) from (with recursive t as(select 0 as n union all select n + 1 as n from t where n + 1 < 20) select n from t))) as x_6
WHERE
  (x_6.value = ((x_4.value) / (2)));

[EvgSkv]

Apparently this is because integer division in SQLite results in an integer number. To make example work we need to do it as follows:

%%logica Even
@Engine("sqlite");

Z(x) :- x in Range(20);

Even(x) :- Z(x), Z(x / 2.0);

We should either change the original (because this form works in BQ as well), or create a standalone SQLite tutorial.

[RAbraham]

changing the original works 👍 . fyi, this happens in postgres too. I'll leave this open if you like to use it as a bookmark but please feel free to close it.