SQLITE Select results into a string

I am looking for a method to return the results of an SQLite query as a single string for use in an internal trigger.

Something like Python's 'somestring'.join() method.

Table: foo
id    |    name
1     |     "foo"
2     |     "bar"
3     |     "bro"

Then a select statement:

MAGIC_STRING_CONCAT_FUNCTION(SELECT id FROM foo,",");

To return "1,2,3"