[Tutor] help with data insert into Access table

[eryksun]

On Wed, Jan 29, 2014 at 3:53 PM, Keith Winston <keithwins at gmail.com> wrote:
> I had the impression that Peter was employing tuples because,
> as an immutable type, it couldn't inadvertently/inauspiciously
> be changed by a user

Per footnote 5 of PEP 249, the parameters need to be in a type that
supports __getitem__ (sequence or mapping). In addition to the qmark
paramstyle, pysqlite (the development name for the sqlite3 module)
supports named parameters:

http://docs.python.org/3/library/sqlite3#sqlite3.Cursor.execute

For a tuple or list of parameters, pysqlite uses the PyTuple and
PyList concrete APIs, respectively. Else for tuple/list subclasses, or
other sequence types, it uses the abstract PySequence API.

Tuples are the sequence of choice because they're allocated more
efficiently, with deallocated tuples cached by size (up to length 20).
Additionally, a tuple of constants is stored directly in the code
object (allowed because it's immutable), while a list has to be built
each time the code is evaluate. For example:

    >>> code = (lambda: ("Site Name's Harbor.JPG",)).__code__

    >>> code.co_consts
    (None, "Site Name's Harbor.JPG", ("Site Name's Harbor.JPG",))

For a dict with named parameters, pysqlite uses the PyDict concrete
API. For a dict subclass (e.g. defaultdict, OrderedDict) it falls back
on the abstract PyMapping API.

Relevant sqlite3 C APIs:

    sqlite3_bind_parameter_count
    sqlite3_bind_parameter_name

https://www.sqlite.org/c3ref/bind_parameter_count.html
https://www.sqlite.org/c3ref/bind_parameter_name.html

    sqlite3_bind_null
    sqlite3_bind_int64
    sqlite3_bind_double
    sqlite3_bind_text
    sqlite3_bind_blob

https://www.sqlite.org/c3ref/bind_blob.html