python-oracledb/samples/object_dump.py

107 lines
4.0 KiB
Python

#------------------------------------------------------------------------------
# Copyright (c) 2023, Oracle and/or its affiliates.
#
# This software is dual-licensed to you under the Universal Permissive License
# (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
# 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose
# either license.
#
# If you elect to accept the software under the Apache License, Version 2.0,
# the following applies:
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# object_dump.py
#
# Shows how to pretty-print an Oracle object or collection.
# Also shows how to insert a Python object to an Oracle object column.
#------------------------------------------------------------------------------
import oracledb
import sample_env
# determine whether to use python-oracledb thin mode or thick mode
if not sample_env.get_is_thin():
oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())
# Create Oracle connection and cursor objects
connection = oracledb.connect(user=sample_env.get_main_user(),
password=sample_env.get_main_password(),
dsn=sample_env.get_connect_string())
cursor = connection.cursor()
# Create a Python class equivalent to an Oracle SDO object
class MySDO(object):
def __init__(self, gtype, elem_info, ordinates):
self.gtype = gtype
self.elem_info = elem_info
self.ordinates = ordinates
# Get Oracle type information
obj_type = connection.gettype("MDSYS.SDO_GEOMETRY")
element_info_type_obj = connection.gettype("MDSYS.SDO_ELEM_INFO_ARRAY")
ordinate_type_obj = connection.gettype("MDSYS.SDO_ORDINATE_ARRAY")
# Convert a Python object to MDSYS.SDO_GEOMETRY
def sdo_input_type_handler(cursor, value, num_elements):
def sdo_in_converter(value):
obj = obj_type.newobject()
obj.SDO_GTYPE = value.gtype
obj.SDO_ELEM_INFO = element_info_type_obj.newobject()
obj.SDO_ELEM_INFO.extend(value.elem_info)
obj.SDO_ORDINATES = ordinate_type_obj.newobject()
obj.SDO_ORDINATES.extend(value.ordinates)
return obj
if isinstance(value, MySDO):
return cursor.var(obj_type, arraysize=num_elements,
inconverter=sdo_in_converter)
# Create and insert a Python object
sdo = MySDO(2003, [1, 1003, 3], [1, 1, 5, 7])
cursor.inputtypehandler = sdo_input_type_handler
cursor.execute("truncate table TestGeometry")
cursor.execute("insert into TestGeometry values (1, :1)", [sdo])
# Define a function to pretty-print the contents of an Oracle object
def dump_object(obj, prefix=""):
if obj.type.iscollection:
print(f"{prefix}[")
for value in obj.aslist():
if isinstance(value, oracledb.DbObject):
dump_object(value, prefix + " ")
else:
print(f"{prefix} {repr(value)}")
print(f"{prefix}]")
else:
print(f"{prefix}{{")
for attr in obj.type.attributes:
value = getattr(obj, attr.name)
if isinstance(value, oracledb.DbObject):
print(f"{prefix} {attr.name}:")
dump_object(value, prefix + " ")
else:
print(f"{prefix} {attr.name}: {repr(value)}")
print(f"{prefix}}}")
# Query the row back
cursor.execute("select geometry from TestGeometry")
for (obj,) in cursor:
dump_object(obj)