Генерируем запрос по всем таблицам:
SELECT
GROUP_CONCAT('select "' || name || '" table_name, * from `' || name || '` where referer = "yandex"', ' union ') q
FROM
sqlite_master
WHERE
type ='table' AND
name NOT LIKE 'sqlite_%';
Получаем:
select "t1" table_name, * from t1 where referer = "yandex" union select "t2" table_name, * from t2 where referer = "yandex"
Выполняем:
+============+====+=========+
| table_name | id | referer |
+============+====+=========+
| t1 | 2 | yandex |
+------------+----+---------+
| t2 | 20 | yandex |
+------------+----+---------+
SQLite fiddle