73 lines
3.0 KiB
Python
73 lines
3.0 KiB
Python
# -----------------------------------------------------------------------------
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# Copyright (c) 2021, 2023, Oracle and/or its affiliates.
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#
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# This software is dual-licensed to you under the Universal Permissive License
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# (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
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# 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose
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# either license.
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#
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# If you elect to accept the software under the Apache License, Version 2.0,
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# the following applies:
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# https://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#------------------------------------------------------------------------------
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#------------------------------------------------------------------------------
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# query_strings_as_bytes.py
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#
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# Demonstrates how to query strings as bytes (bypassing decoding of the bytes
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# into a Python string). This can be useful when attempting to fetch data that
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# was stored in the database in the wrong encoding.
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#------------------------------------------------------------------------------
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import oracledb
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import sample_env
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# determine whether to use python-oracledb thin mode or thick mode
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if not sample_env.get_is_thin():
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oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())
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STRING_VAL = 'I bought a cafetière on the Champs-Élysées'
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def return_strings_as_bytes(cursor, metadata):
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if metadata.type_code is oracledb.DB_TYPE_VARCHAR:
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return cursor.var(str, arraysize=cursor.arraysize, bypass_decode=True)
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connection = oracledb.connect(user=sample_env.get_main_user(),
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password=sample_env.get_main_password(),
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dsn=sample_env.get_connect_string())
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# truncate table and populate with our data of choice
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with connection.cursor() as cursor:
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cursor.execute("truncate table TestTempTable")
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cursor.execute("insert into TestTempTable values (1, :val)",
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val=STRING_VAL)
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connection.commit()
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# fetch the data normally and show that it is returned as a string
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with connection.cursor() as cursor:
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cursor.execute("select IntCol, StringCol from TestTempTable")
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print("Data fetched using normal technique:")
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for row in cursor:
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print(row)
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print()
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# fetch the data, bypassing the decode and show that it is returned as
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# bytes
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with connection.cursor() as cursor:
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cursor.outputtypehandler = return_strings_as_bytes
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cursor.execute("select IntCol, StringCol from TestTempTable")
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print("Data fetched using bypass decode technique:")
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for row in cursor:
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print(row)
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