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Diffstat (limited to 'lib/sqlalchemy/dialects/sqlite/json.py')
-rw-r--r-- | lib/sqlalchemy/dialects/sqlite/json.py | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/lib/sqlalchemy/dialects/sqlite/json.py b/lib/sqlalchemy/dialects/sqlite/json.py new file mode 100644 index 000000000..90929fbd8 --- /dev/null +++ b/lib/sqlalchemy/dialects/sqlite/json.py @@ -0,0 +1,77 @@ +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. + + 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 + + .. seealso:: + + JSON1_ + + .. _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 + ]) + ) |