119 lines
4.2 KiB
Python
119 lines
4.2 KiB
Python
#------------------------------------------------------------------------------
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# Copyright (c) 2020, 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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# json_blob.py
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#
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# Demonstrates how to use a BLOB as a JSON column store.
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#
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# Note: Oracle Database 12c lets JSON be stored in VARCHAR2 or LOB columns.
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# With Oracle Database 21c using the new JSON type is recommended
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# instead, see json_direct.py
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#
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# Documentation:
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# python-oracledb: https://oracledb.readthedocs.io/en/latest/user_guide/json_data_type.html
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# Oracle Database: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=ADJSN
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#------------------------------------------------------------------------------
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import json
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import sys
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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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# use the feature that transforms JSON data in VARCHAR2 and LOB columns to
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# objects
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oracledb.__future__.old_json_col_as_obj = 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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if not connection.thin:
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client_version = oracledb.clientversion()[0]
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db_version = int(connection.version.split(".")[0])
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# Minimum database vesion is 12
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if db_version < 12:
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sys.exit("This example requires Oracle Database 12.1.0.2 or later")
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# Insert JSON data
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with connection.cursor() as cursor:
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data = dict(name="Rod", dept="Sales", location="Germany")
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inssql = "insert into CustomersAsBlob values (:1, :2)"
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if (connection.thin or client_version >= 21) and db_version >= 21:
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# Take advantage of direct binding
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cursor.setinputsizes(None, oracledb.DB_TYPE_JSON)
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cursor.execute(inssql, [1, data])
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else:
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# Insert the data as a JSON string
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cursor.execute(inssql, [1, json.dumps(data)])
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# Select JSON data
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with connection.cursor() as cursor:
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sql = "select c.json_data from CustomersAsBlob c"
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for j, in cursor.execute(sql):
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print(j)
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# Using JSON_VALUE to extract a value from a JSON column
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sql = """select json_value(json_data, '$.location')
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from CustomersAsBlob
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offset 0 rows fetch next 1 rows only"""
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for r in cursor.execute(sql):
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print(r)
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# Using dot-notation to extract a value from a JSON (BLOB storage) column
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sql = """select c.json_data.location
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from CustomersAsBlob c
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offset 0 rows fetch next 1 rows only"""
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for j, in cursor.execute(sql):
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print(j)
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# Using JSON_OBJECT to extract relational data as JSON
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sql = """select json_object('key' is d.dummy) dummy
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from dual d"""
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for r in cursor.execute(sql):
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print(r)
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# Using JSON_ARRAYAGG to extract a whole relational table as JSON
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oracledb.defaults.fetch_lobs = False
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sql = """select json_arrayagg(
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json_object('key' is c.id,
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'name' is c.json_data)
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returning clob)
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from CustomersAsBlob c"""
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for r in cursor.execute(sql):
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print(r)
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