SQLite3 run a trigger insert multiple times besed on inserted vlaue - sqlite

Question

Want to run an insert n-times, the n is defined by inserted value on another table.
table 1:
create table Table1
(
id INTEGER default 1 not null
primary key
unique,
name TEXT not null
unique,
keys_number INTEGER default 1 not null
);
table 2:
create table table_2
(
id INTEGER default 1 not null
primary key
unique,
table_1_id INTEGER not null
references table_1,
);
Now when i insert into table_1 like:
INSERT INT table_1 (name, keys_number) VALUES ('dummy_name', 5)
want to run a trigger
CREATE TRIGGER insert_keys_after_insert_table_1
AFTER INSERT ON table_1
WHEN (SELECT COUNT(*) FROM table_2 WHERE table_1_id=new.id) < new.keys_number
BEGIN
INSERT INTO keys (table_1_id) VALUES (new.id);
END;
But this runs only once.
Finally, I want to have on table_2 values after the trigger
INSERT INT table_1 (name, keys_number) VALUES ('dummy_name_1', 5)
make the result like:
id;name;keys_number
1;dummy_name_1;5
and the result on table_2 after the trigger, should be
id;table_1_id
1;1
2;1
3;1
4;1
5;1
or if I insert another one on table_1
INSERT INT table_1 (name, keys_number) VALUES ('dummy_name_2', 2)
will make the result on table_1 like:
id;name;keys_number
1;dummy_name_1;5
2;dummy_name_2;2
and the trigger will give the result on table_2:
id;table_1_id
1;1
2;1
3;1
4;1
5;1
6;2
7;2

Answer 1

For this requirement you need a loop, which in SQL is implemented via a recursive CTE.
Unfortunately SQLite does not allow CTEs inside a trigger.
A workaround is to create a new table with only 1 column which will store the numbers 1 to the max expected value of keys_number in table_1:
CREATE TABLE table_numbers AS
WITH cte(keys_number) AS (
SELECT 1
UNION ALL
SELECT keys_number + 1 FROM cte WHERE keys_number < 100 -- change 100 to the max keys_number you expect
)
SELECT keys_number FROM cte
Now you can create your trigger:
CREATE TRIGGER insert_keys_after_insert_table_1 AFTER INSERT ON table_1
BEGIN
INSERT INTO table_2(table_1_id)
SELECT NEW.id
FROM table_numbers
WHERE keys_number <= NEW.keys_number - (SELECT COUNT(*) FROM table_2 WHERE table_1_id = NEW.id);
END;
See the demo.