I think I've found a little bug or at least an inconsistent
behavior in the executemany() method.
Using the execute() method to insert an overflowing string
in a VARCHAR field (e.g.: inserting a 256 chars string in
a VARCHAR(255) field) will not raise any Warning, while
the string is - obviously - truncated.
The same behavior can be seen using the executemany()
with just a single value.
On the other side, using the executemany() method to insert
more than one row (with at least one of them too long),
raise a Warning.
In the attachment I've put a very simple example.