SQLite Forum

When committed changes become visible to connections that ATTACH?
Login
On a single database connection, 
when a query begins, it starts a read transaction.  Other queries that
come along before the first query ended piggy-back onto the original
read transaction. This continues, holding the transaction open, until
all queries are complete.

While a read-transaction is active, SQLite sees a single consistent
snapshot of the data.  Changes added by other database connections after
the read transaction started are invisible to the read transaction.
This is a feature, not a bug.

If you want to see all the latest changes entered by other database
connections, you have to end your read transaction and start a new one.