def _solve_conn_curs(conn_or_curs):
"""Return the connection and a DBAPI cursor from a connection or cursor."""
if conn_or_curs is None:
raise psycopg2.ProgrammingError("no connection or cursor provided")
if hasattr(conn_or_curs, 'execute'):
conn = conn_or_curs.connection
curs = conn.cursor(cursor_factory=_cursor)
else:
conn = conn_or_curs
curs = conn.cursor(cursor_factory=_cursor)
return conn, curs
def _from_db(self, name, conn_or_curs):
"""Return a `CompositeCaster` instance for the type *name*.
Raise `ProgrammingError` if the type is not found.
"""
conn, curs = _solve_conn_curs(conn_or_curs)
# Store the transaction status of the connection to revert it after use
conn_status = conn.status
# Use the correct schema
if '.' in name:
schema, tname = name.split('.', 1)
else:
tname = name
schema = 'public'
# column typarray not available before PG 8.3
typarray = conn.server_version >= 80300 and "typarray" or "NULL"
# get the type oid and attributes
curs.execute(
"""\
SELECT t.oid, %s, attname, atttypid
FROM pg_type t
JOIN pg_namespace ns ON typnamespace = ns.oid
JOIN pg_attribute a ON attrelid = typrelid
WHERE typname = %%s AND nspname = %%s
AND attnum > 0 AND NOT attisdropped
ORDER BY attnum;
""" % typarray, (tname, schema))
recs = curs.fetchall()
# revert the status of the connection as before the command
if (conn_status != _ext.STATUS_IN_TRANSACTION and not conn.autocommit):
conn.rollback()
if not recs:
raise psycopg2.ProgrammingError("PostgreSQL type '%s' not found" %
name)
type_oid = recs[0][0]
array_oid = recs[0][1]
type_attrs = [(r[2], r[3]) for r in recs]
return self(tname,
type_oid,
type_attrs,
array_oid=array_oid,
schema=schema)
def register_hstore(conn_or_curs,
globally=False,
unicode=False,
oid=None,
array_oid=None):
"""Register adapter and typecaster for `!dict`\-\ |hstore| conversions.
:param conn_or_curs: a connection or cursor: the typecaster will be
registered only on this object unless *globally* is set to `!True`
:param globally: register the adapter globally, not only on *conn_or_curs*
:param unicode: if `!True`, keys and values returned from the database
will be `!unicode` instead of `!str`. The option is not available on
Python 3
:param oid: the OID of the |hstore| type if known. If not, it will be
queried on *conn_or_curs*.
:param array_oid: the OID of the |hstore| array type if known. If not, it
will be queried on *conn_or_curs*.
The connection or cursor passed to the function will be used to query the
database and look for the OID of the |hstore| type (which may be different
across databases). If querying is not desirable (e.g. with
:ref:`asynchronous connections <async-support>`) you may specify it in the
*oid* parameter, which can be found using a query such as :sql:`SELECT
'hstore'::regtype::oid`. Analogously you can obtain a value for *array_oid*
using a query such as :sql:`SELECT 'hstore[]'::regtype::oid`.
Note that, when passing a dictionary from Python to the database, both
strings and unicode keys and values are supported. Dictionaries returned
from the database have keys/values according to the *unicode* parameter.
The |hstore| contrib module must be already installed in the database
(executing the ``hstore.sql`` script in your ``contrib`` directory).
Raise `~psycopg2.ProgrammingError` if the type is not found.
"""
if oid is None:
oid = HstoreAdapter.get_oids(conn_or_curs)
if oid is None or not oid[0]:
raise psycopg2.ProgrammingError(
"hstore type not found in the database. "
"please install it from your 'contrib/hstore.sql' file")
else:
array_oid = oid[1]
oid = oid[0]
if isinstance(oid, int):
oid = (oid, )
if array_oid is not None:
if isinstance(array_oid, int):
array_oid = (array_oid, )
else:
array_oid = tuple([x for x in array_oid if x])
# create and register the typecaster
if _sys.version_info[0] < 3 and unicode:
cast = HstoreAdapter.parse_unicode
else:
cast = HstoreAdapter.parse
HSTORE = _ext.new_type(oid, "HSTORE", cast)
_ext.register_type(HSTORE, not globally and conn_or_curs or None)
_ext.register_adapter(dict, HstoreAdapter)
if array_oid:
HSTOREARRAY = _ext.new_array_type(array_oid, "HSTOREARRAY", HSTORE)
_ext.register_type(HSTOREARRAY, not globally and conn_or_curs or None)
