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-rw-r--r--lib/sqlalchemy/dialects/postgresql/__init__.py3
-rw-r--r--lib/sqlalchemy/dialects/postgresql/base.py3
-rw-r--r--lib/sqlalchemy/dialects/postgresql/pgjson.py128
-rw-r--r--lib/sqlalchemy/dialects/postgresql/psycopg2.py15
4 files changed, 148 insertions, 1 deletions
diff --git a/lib/sqlalchemy/dialects/postgresql/__init__.py b/lib/sqlalchemy/dialects/postgresql/__init__.py
index 3c1d19504..728f1629f 100644
--- a/lib/sqlalchemy/dialects/postgresql/__init__.py
+++ b/lib/sqlalchemy/dialects/postgresql/__init__.py
@@ -15,6 +15,7 @@ from .base import \
TSVECTOR
from .constraints import ExcludeConstraint
from .hstore import HSTORE, hstore
+from .pgjson import JSON
from .ranges import INT4RANGE, INT8RANGE, NUMRANGE, DATERANGE, TSRANGE, \
TSTZRANGE
@@ -24,5 +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', 'TSVECTOR'
+ 'TSRANGE', 'TSTZRANGE', 'json', 'JSON'
)
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index d3380afdd..a7f838009 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -1246,6 +1246,9 @@ class PGTypeCompiler(compiler.GenericTypeCompiler):
def visit_HSTORE(self, type_):
return "HSTORE"
+ def visit_JSON(self, type_):
+ return "JSON"
+
def visit_INT4RANGE(self, type_):
return "INT4RANGE"
diff --git a/lib/sqlalchemy/dialects/postgresql/pgjson.py b/lib/sqlalchemy/dialects/postgresql/pgjson.py
new file mode 100644
index 000000000..a29d0bbcc
--- /dev/null
+++ b/lib/sqlalchemy/dialects/postgresql/pgjson.py
@@ -0,0 +1,128 @@
+# postgresql/json.py
+# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+
+import json
+
+from .base import ARRAY, ischema_names
+from ... import types as sqltypes
+from ...sql import functions as sqlfunc
+from ...sql.operators import custom_op
+from ... import util
+
+__all__ = ('JSON', 'json')
+
+
+class JSON(sqltypes.TypeEngine):
+ """Represent the Postgresql JSON type.
+
+ The :class:`.JSON` type stores arbitrary JSON format data, e.g.::
+
+ data_table = Table('data_table', metadata,
+ Column('id', Integer, primary_key=True),
+ Column('data', JSON)
+ )
+
+ with engine.connect() as conn:
+ conn.execute(
+ data_table.insert(),
+ data = {"key1": "value1", "key2": "value2"}
+ )
+
+ :class:`.JSON` provides several operations:
+
+ * Index operations::
+
+ data_table.c.data['some key']
+
+ * Index operations returning text (required for text comparison or casting)::
+
+ data_table.c.data.get_item_as_text('some key') == 'some value'
+
+ * Path index operations::
+
+ data_table.c.data.get_path("{key_1, key_2, ..., key_n}")
+
+ * Path index operations returning text (required for text comparison or casting)::
+
+ data_table.c.data.get_path("{key_1, key_2, ..., key_n}") == 'some value'
+
+ Please be aware that when used with the SQLAlchemy ORM, you will need to
+ replace the JSON object present on an attribute with a new object in order
+ for any changes to be properly persisted.
+
+ .. versionadded:: 0.9
+ """
+
+ __visit_name__ = 'JSON'
+
+ def __init__(self, json_serializer=None, json_deserializer=None):
+ if json_serializer:
+ self.json_serializer = json_serializer
+ else:
+ self.json_serializer = json.dumps
+ if json_deserializer:
+ self.json_deserializer = json_deserializer
+ else:
+ self.json_deserializer = json.loads
+
+ class comparator_factory(sqltypes.Concatenable.Comparator):
+ """Define comparison operations for :class:`.JSON`."""
+
+ def __getitem__(self, other):
+ """Text expression. Get the value at a given key."""
+ # I'm choosing to return text here so the result can be cast,
+ # compared with strings, etc.
+ #
+ # The only downside to this is that you cannot dereference more
+ # than one level deep in json structures, though comparator
+ # support for multi-level dereference is lacking anyhow.
+ return self.expr.op('->', precedence=5)(other)
+
+ def get_item_as_text(self, other):
+ """Text expression. Get the value at the given key as text. Use
+ this when you need to cast the type of the returned value."""
+ return self.expr.op('->>', precedence=5)(other)
+
+ def get_path(self, other):
+ """Text expression. Get the value at a given path. Paths are of
+ the form {key_1, key_2, ..., key_n}."""
+ return self.expr.op('#>', precedence=5)(other)
+
+ def get_path_as_text(self, other):
+ """Text expression. Get the value at a given path, as text.
+ Paths are of the form {key_1, key_2, ..., key_n}. Use this when
+ you need to cast the type of the returned value."""
+ return self.expr.op('#>>', precedence=5)(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):
+ if util.py2k:
+ encoding = dialect.encoding
+ def process(value):
+ return self.json_serializer(value).encode(encoding)
+ else:
+ def process(value):
+ return self.json_serializer(value)
+ return process
+
+ def result_processor(self, dialect, coltype):
+ if util.py2k:
+ encoding = dialect.encoding
+ def process(value):
+ return self.json_deserializer(value.decode(encoding))
+ else:
+ def process(value):
+ return self.json_deserializer(value)
+ return process
+
+
+ischema_names['json'] = JSON
diff --git a/lib/sqlalchemy/dialects/postgresql/psycopg2.py b/lib/sqlalchemy/dialects/postgresql/psycopg2.py
index c3c749523..4a9248e5f 100644
--- a/lib/sqlalchemy/dialects/postgresql/psycopg2.py
+++ b/lib/sqlalchemy/dialects/postgresql/psycopg2.py
@@ -179,6 +179,7 @@ from .base import PGDialect, PGCompiler, \
ENUM, ARRAY, _DECIMAL_TYPES, _FLOAT_TYPES,\
_INT_TYPES
from .hstore import HSTORE
+from .pgjson import JSON
logger = logging.getLogger('sqlalchemy.dialects.postgresql')
@@ -233,6 +234,17 @@ class _PGHStore(HSTORE):
else:
return super(_PGHStore, self).result_processor(dialect, coltype)
+
+class _PGJSON(JSON):
+ # I've omitted the bind processor here because the method of serializing
+ # involves registering specific types to auto-serialize, and the adapter
+ # just a thin wrapper over json.dumps.
+ def result_processor(self, dialect, coltype):
+ if dialect._has_native_json:
+ return None
+ else:
+ return super(_PGJSON, self).result_processor(dialect, coltype)
+
# When we're handed literal SQL, ensure it's a SELECT-query. Since
# 8.3, combining cursors and "FOR UPDATE" has been fine.
SERVER_SIDE_CURSOR_RE = re.compile(
@@ -317,6 +329,7 @@ class PGDialect_psycopg2(PGDialect):
psycopg2_version = (0, 0)
_has_native_hstore = False
+ _has_native_json = False
colspecs = util.update_copy(
PGDialect.colspecs,
@@ -325,6 +338,7 @@ class PGDialect_psycopg2(PGDialect):
ENUM: _PGEnum, # needs force_unicode
sqltypes.Enum: _PGEnum, # needs force_unicode
HSTORE: _PGHStore,
+ JSON: _PGJSON
}
)
@@ -352,6 +366,7 @@ class PGDialect_psycopg2(PGDialect):
self._has_native_hstore = self.use_native_hstore and \
self._hstore_oids(connection.connection) \
is not None
+ self._has_native_json = self.psycopg2_version >= (2, 5)
@classmethod
def dbapi(cls):
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