Current File : /lib64/python2.7/site-packages/sqlalchemy/dialects/sqlite//json.py
# dialects/sqlite/json.py
# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: https://www.opensource.org/licenses/mit-license.php
from ... import types as sqltypes
class JSON(sqltypes.JSON):
"""SQLite JSON type.
SQLite supports JSON as of version 3.9 through its JSON1_ extension. Note
that JSON1_ is a
`loadable extension <https://www.sqlite.org/loadext.html>`_ and as such
may not be available, or may require run-time loading.
:class:`_sqlite.JSON` is used automatically whenever the base
:class:`_types.JSON` datatype is used against a SQLite backend.
.. seealso::
:class:`_types.JSON` - main documentation for the generic
cross-platform JSON datatype.
The :class:`_sqlite.JSON` type supports persistence of JSON values
as well as the core index operations provided by :class:`_types.JSON`
datatype, by adapting the operations to render the ``JSON_EXTRACT``
function wrapped in the ``JSON_QUOTE`` function at the database level.
Extracted values are quoted in order to ensure that the results are
always JSON string values.
.. versionadded:: 1.3
.. _JSON1: https://www.sqlite.org/json1.html
"""
# Note: these objects currently match exactly those of MySQL, however since
# these are not generalizable to all JSON implementations, remain separately
# implemented for each dialect.
class _FormatTypeMixin(object):
def _format_value(self, value):
raise NotImplementedError()
def bind_processor(self, dialect):
super_proc = self.string_bind_processor(dialect)
def process(value):
value = self._format_value(value)
if super_proc:
value = super_proc(value)
return value
return process
def literal_processor(self, dialect):
super_proc = self.string_literal_processor(dialect)
def process(value):
value = self._format_value(value)
if super_proc:
value = super_proc(value)
return value
return process
class JSONIndexType(_FormatTypeMixin, sqltypes.JSON.JSONIndexType):
def _format_value(self, value):
if isinstance(value, int):
value = "$[%s]" % value
else:
value = '$."%s"' % value
return value
class JSONPathType(_FormatTypeMixin, sqltypes.JSON.JSONPathType):
def _format_value(self, value):
return "$%s" % (
"".join(
[
"[%s]" % elem if isinstance(elem, int) else '."%s"' % elem
for elem in value
]
)
)
