174 lines
6.0 KiB
Python
174 lines
6.0 KiB
Python
from ... import exc
|
|
from ... import util
|
|
from ...sql.base import _exclusive_against
|
|
from ...sql.base import _generative
|
|
from ...sql.base import ColumnCollection
|
|
from ...sql.dml import Insert as StandardInsert
|
|
from ...sql.elements import ClauseElement
|
|
from ...sql.expression import alias
|
|
from ...util.langhelpers import public_factory
|
|
|
|
|
|
__all__ = ("Insert", "insert")
|
|
|
|
|
|
class Insert(StandardInsert):
|
|
"""MySQL-specific implementation of INSERT.
|
|
|
|
Adds methods for MySQL-specific syntaxes such as ON DUPLICATE KEY UPDATE.
|
|
|
|
The :class:`~.mysql.Insert` object is created using the
|
|
:func:`sqlalchemy.dialects.mysql.insert` function.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
"""
|
|
|
|
stringify_dialect = "mysql"
|
|
|
|
@property
|
|
def inserted(self):
|
|
"""Provide the "inserted" namespace for an ON DUPLICATE KEY UPDATE statement
|
|
|
|
MySQL's ON DUPLICATE KEY UPDATE clause allows reference to the row
|
|
that would be inserted, via a special function called ``VALUES()``.
|
|
This attribute provides all columns in this row to be referenceable
|
|
such that they will render within a ``VALUES()`` function inside the
|
|
ON DUPLICATE KEY UPDATE clause. The attribute is named ``.inserted``
|
|
so as not to conflict with the existing
|
|
:meth:`_expression.Insert.values` method.
|
|
|
|
.. tip:: The :attr:`_mysql.Insert.inserted` attribute is an instance
|
|
of :class:`_expression.ColumnCollection`, which provides an
|
|
interface the same as that of the :attr:`_schema.Table.c`
|
|
collection described at :ref:`metadata_tables_and_columns`.
|
|
With this collection, ordinary names are accessible like attributes
|
|
(e.g. ``stmt.inserted.some_column``), but special names and
|
|
dictionary method names should be accessed using indexed access,
|
|
such as ``stmt.inserted["column name"]`` or
|
|
``stmt.inserted["values"]``. See the docstring for
|
|
:class:`_expression.ColumnCollection` for further examples.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`mysql_insert_on_duplicate_key_update` - example of how
|
|
to use :attr:`_expression.Insert.inserted`
|
|
|
|
"""
|
|
return self.inserted_alias.columns
|
|
|
|
@util.memoized_property
|
|
def inserted_alias(self):
|
|
return alias(self.table, name="inserted")
|
|
|
|
@_generative
|
|
@_exclusive_against(
|
|
"_post_values_clause",
|
|
msgs={
|
|
"_post_values_clause": "This Insert construct already "
|
|
"has an ON DUPLICATE KEY clause present"
|
|
},
|
|
)
|
|
def on_duplicate_key_update(self, *args, **kw):
|
|
r"""
|
|
Specifies the ON DUPLICATE KEY UPDATE clause.
|
|
|
|
:param \**kw: Column keys linked to UPDATE values. The
|
|
values may be any SQL expression or supported literal Python
|
|
values.
|
|
|
|
.. warning:: This dictionary does **not** take into account
|
|
Python-specified default UPDATE values or generation functions,
|
|
e.g. those specified using :paramref:`_schema.Column.onupdate`.
|
|
These values will not be exercised for an ON DUPLICATE KEY UPDATE
|
|
style of UPDATE, unless values are manually specified here.
|
|
|
|
:param \*args: As an alternative to passing key/value parameters,
|
|
a dictionary or list of 2-tuples can be passed as a single positional
|
|
argument.
|
|
|
|
Passing a single dictionary is equivalent to the keyword argument
|
|
form::
|
|
|
|
insert().on_duplicate_key_update({"name": "some name"})
|
|
|
|
Passing a list of 2-tuples indicates that the parameter assignments
|
|
in the UPDATE clause should be ordered as sent, in a manner similar
|
|
to that described for the :class:`_expression.Update`
|
|
construct overall
|
|
in :ref:`updates_order_parameters`::
|
|
|
|
insert().on_duplicate_key_update(
|
|
[("name", "some name"), ("value", "some value")])
|
|
|
|
.. versionchanged:: 1.3 parameters can be specified as a dictionary
|
|
or list of 2-tuples; the latter form provides for parameter
|
|
ordering.
|
|
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. seealso::
|
|
|
|
:ref:`mysql_insert_on_duplicate_key_update`
|
|
|
|
"""
|
|
if args and kw:
|
|
raise exc.ArgumentError(
|
|
"Can't pass kwargs and positional arguments simultaneously"
|
|
)
|
|
|
|
if args:
|
|
if len(args) > 1:
|
|
raise exc.ArgumentError(
|
|
"Only a single dictionary or list of tuples "
|
|
"is accepted positionally."
|
|
)
|
|
values = args[0]
|
|
else:
|
|
values = kw
|
|
|
|
inserted_alias = getattr(self, "inserted_alias", None)
|
|
self._post_values_clause = OnDuplicateClause(inserted_alias, values)
|
|
|
|
|
|
insert = public_factory(
|
|
Insert, ".dialects.mysql.insert", ".dialects.mysql.Insert"
|
|
)
|
|
|
|
|
|
class OnDuplicateClause(ClauseElement):
|
|
__visit_name__ = "on_duplicate_key_update"
|
|
|
|
_parameter_ordering = None
|
|
|
|
stringify_dialect = "mysql"
|
|
|
|
def __init__(self, inserted_alias, update):
|
|
self.inserted_alias = inserted_alias
|
|
|
|
# auto-detect that parameters should be ordered. This is copied from
|
|
# Update._proces_colparams(), however we don't look for a special flag
|
|
# in this case since we are not disambiguating from other use cases as
|
|
# we are in Update.values().
|
|
if isinstance(update, list) and (
|
|
update and isinstance(update[0], tuple)
|
|
):
|
|
self._parameter_ordering = [key for key, value in update]
|
|
update = dict(update)
|
|
|
|
if isinstance(update, dict):
|
|
if not update:
|
|
raise ValueError(
|
|
"update parameter dictionary must not be empty"
|
|
)
|
|
elif isinstance(update, ColumnCollection):
|
|
update = dict(update)
|
|
else:
|
|
raise ValueError(
|
|
"update parameter must be a non-empty dictionary "
|
|
"or a ColumnCollection such as the `.c.` collection "
|
|
"of a Table object"
|
|
)
|
|
self.update = update
|