Sqlite3 date operations when joining two tables in a view?

Long story short, how can I add minutes to a datetime from an integer located in another table in one of the select statements by concatenating them in sqlite3?

I have sqlite3 db with:

table P (int id, ..., int minutes) and table S (int id, int p_id, start datetime)

I want to create a view that gives me PS (S.id, P.id, S.start + P.minutes) by joining S.p_id = P.id

The problem is that if I create a request from the application, I can do things like:

select datetime('2010-04-21 14:00', '+20 minutes');
2010-04-21 14:20:00

      

        
        
        
      

    

By creating the string "+20 minutes" in the application, and then passing it to sqlite. However, I cannot find a way to create this line in the select itself:

select p.*,datetime(s.start_at, formatstring('+%s minutes', p.minutes)) from p,s where s.p_id=p.id;

      

        
        
        
      

    

Since sqlite, as the documentation says, does not provide any string format function, and I see no alternative way to express date modifiers.

In MySQL, date modifiers are not string-based, so it actually works:

mysql> create table p ( id integer, minutes integer);
mysql> create table s ( id integer, p_id integer, start datetime);
mysql> insert into p values (1, 10);
mysql> insert into p values (2, 15);
mysql> insert into s values (1, 1, '2008-12-31 14:00');
mysql> insert into s values (2, 1, '2008-12-31 15:00');
mysql> insert into s values (3, 2, '2008-05-10 13:30');
mysql> SELECT p.*,(s.start + INTERVAL p.minutes MINUTE) FROM p,s WHERE p.id=s.p_id;
+------+---------+---------------------------------------+
| id   | minutes | (s.start + INTERVAL p.minutes MINUTE) |
+------+---------+---------------------------------------+
|    1 |      10 | 2008-12-31 14:10:00                   | 
|    1 |      10 | 2008-12-31 15:10:00                   | 
|    2 |      15 | 2008-05-10 13:45:00                   | 
+------+---------+---------------------------------------+
3 rows in set (0.02 sec)