(PHP 5 >= 5.3.0, PHP 7, PHP 8)
SQLite3::lastInsertRowID — Returns the row ID of the most recent INSERT into the database
Returns the row ID of the most recent INSERT into the database.
This function has no parameters.
Returns the row ID of the most recent INSERT into the database.
If no successful INSERTs into rowid tables have ever occurred on this database connection,
then SQLite3::lastInsertRowID() returns 0.
lastInsertRowID is relative to the database connection. Hence if there are two instances of a php script (with distinct $db connections) there is no risk that the RowID of the one instance will effect the result of the other instance.
I mention this point here as it was not clear from the documentation, at least not very clear to me and hence I hope it might help others.