From: Damian Dimmich Date: Tue, 24 Jun 2014 07:23:21 +0000 (+0400) Subject: initial support for JSONB - this only allows you to define the JSONB X-Git-Tag: rel_1_0_0b1~349^2~5 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=01cc8fbacce8f571a47a3617b913e579bd666f97;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git initial support for JSONB - this only allows you to define the JSONB datatype - this does not add any of the additional support for querying/indexing yet. --- diff --git a/lib/sqlalchemy/dialects/postgresql/__init__.py b/lib/sqlalchemy/dialects/postgresql/__init__.py index d1c768186d..1ed43b6351 100644 --- a/lib/sqlalchemy/dialects/postgresql/__init__.py +++ b/lib/sqlalchemy/dialects/postgresql/__init__.py @@ -15,7 +15,7 @@ from .base import \ TSVECTOR from .constraints import ExcludeConstraint from .hstore import HSTORE, hstore -from .json import JSON, JSONElement +from .json import JSON, JSONElement, JSONB from .ranges import INT4RANGE, INT8RANGE, NUMRANGE, DATERANGE, TSRANGE, \ TSTZRANGE @@ -25,5 +25,5 @@ __all__ = ( 'DOUBLE_PRECISION', 'TIMESTAMP', 'TIME', 'DATE', 'BYTEA', 'BOOLEAN', 'INTERVAL', 'ARRAY', 'ENUM', 'dialect', 'Any', 'All', 'array', 'HSTORE', 'hstore', 'INT4RANGE', 'INT8RANGE', 'NUMRANGE', 'DATERANGE', - 'TSRANGE', 'TSTZRANGE', 'json', 'JSON', 'JSONElement' + 'TSRANGE', 'TSTZRANGE', 'json', 'JSON', 'JSONB', 'JSONElement' ) diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py index 35f3352529..6c4031b018 100644 --- a/lib/sqlalchemy/dialects/postgresql/base.py +++ b/lib/sqlalchemy/dialects/postgresql/base.py @@ -1384,6 +1384,9 @@ class PGTypeCompiler(compiler.GenericTypeCompiler): def visit_JSON(self, type_): return "JSON" + def visit_JSONB(self, type_): + return "JSONB" + def visit_INT4RANGE(self, type_): return "INT4RANGE" diff --git a/lib/sqlalchemy/dialects/postgresql/json.py b/lib/sqlalchemy/dialects/postgresql/json.py index 2e29185e8a..37196dfb18 100644 --- a/lib/sqlalchemy/dialects/postgresql/json.py +++ b/lib/sqlalchemy/dialects/postgresql/json.py @@ -14,7 +14,7 @@ from ... import sql from ...sql import elements from ... import util -__all__ = ('JSON', 'JSONElement') +__all__ = ('JSON', 'JSONElement', 'JSONB') class JSONElement(elements.BinaryExpression): @@ -197,3 +197,114 @@ class JSON(sqltypes.TypeEngine): ischema_names['json'] = JSON + + + +class JSONB(sqltypes.TypeEngine): + """Represent the Postgresql JSONB type. + + The :class:`.JSONB` type stores arbitrary JSONB format data, e.g.:: + + data_table = Table('data_table', metadata, + Column('id', Integer, primary_key=True), + Column('data', JSONB) + ) + + with engine.connect() as conn: + conn.execute( + data_table.insert(), + data = {"key1": "value1", "key2": "value2"} + ) + + :class:`.JSONB` provides several operations: + + * Index operations:: + + data_table.c.data['some key'] + + * Index operations returning text (required for text comparison):: + + data_table.c.data['some key'].astext == 'some value' + + * Index operations with a built-in CAST call:: + + data_table.c.data['some key'].cast(Integer) == 5 + + * Path index operations:: + + data_table.c.data[('key_1', 'key_2', ..., 'key_n')] + + * Path index operations returning text (required for text comparison):: + + data_table.c.data[('key_1', 'key_2', ..., 'key_n')].astext == 'some value' + + Index operations return an instance of :class:`.JSONElement`, which represents + an expression such as ``column -> index``. This element then defines + methods such as :attr:`.JSONElement.astext` and :meth:`.JSONElement.cast` + for setting up type behavior. + + The :class:`.JSON` type, when used with the SQLAlchemy ORM, does not detect + in-place mutations to the structure. In order to detect these, the + :mod:`sqlalchemy.ext.mutable` extension must be used. This extension will + allow "in-place" changes to the datastructure to produce events which + will be detected by the unit of work. See the example at :class:`.HSTORE` + for a simple example involving a dictionary. + + Custom serializers and deserializers are specified at the dialect level, + that is using :func:`.create_engine`. The reason for this is that when + using psycopg2, the DBAPI only allows serializers at the per-cursor + or per-connection level. E.g.:: + + engine = create_engine("postgresql://scott:tiger@localhost/test", + json_serializer=my_serialize_fn, + json_deserializer=my_deserialize_fn + ) + + When using the psycopg2 dialect, the json_deserializer is registered + against the database using ``psycopg2.extras.register_default_json``. + + .. versionadded:: 0.9.7 + + """ + + __visit_name__ = 'JSONB' + + class comparator_factory(sqltypes.Concatenable.Comparator): + """Define comparison operations for :class:`.JSON`.""" + + def __getitem__(self, other): + """Get the value at a given key.""" + + return JSONElement(self.expr, other) + + def _adapt_expression(self, op, other_comparator): + if isinstance(op, custom_op): + if op.opstring == '->': + return op, sqltypes.Text + return sqltypes.Concatenable.Comparator.\ + _adapt_expression(self, op, other_comparator) + + def bind_processor(self, dialect): + json_serializer = dialect._json_serializer or json.dumps + if util.py2k: + encoding = dialect.encoding + def process(value): + return json_serializer(value).encode(encoding) + else: + def process(value): + return json_serializer(value) + return process + + def result_processor(self, dialect, coltype): + json_deserializer = dialect._json_deserializer or json.loads + if util.py2k: + encoding = dialect.encoding + def process(value): + return json_deserializer(value.decode(encoding)) + else: + def process(value): + return json_deserializer(value) + return process + + +ischema_names['jsonb'] = JSONB \ No newline at end of file