94 lines
3.4 KiB
Python
94 lines
3.4 KiB
Python
#------------------------------------------------------------------------------
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# Copyright (c) 2016, 2022, Oracle and/or its affiliates.
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#
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# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
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#
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# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
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# Canada. All rights reserved.
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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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# scrollable_cursors.py
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#
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# Demonstrates how to use scrollable cursors. These allow moving forward and
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# backward in the result set but incur additional overhead on the server to
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# retain this information.
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#------------------------------------------------------------------------------
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import oracledb
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import sample_env
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# this script is currently only supported in python-oracledb thick mode
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oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())
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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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# show all of the rows available in the table
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with connection.cursor() as cursor:
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cursor.execute("select * from TestStrings order by IntCol")
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print("ALL ROWS")
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for row in cursor:
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print(row)
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print()
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# create a scrollable cursor
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with connection.cursor(scrollable = True) as cursor:
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# set array size smaller than the default (100) to force scrolling by the
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# database; otherwise, scrolling occurs directly within the buffers
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cursor.arraysize = 3
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cursor.execute("select * from TestStrings order by IntCol")
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# scroll to last row in the result set; the first parameter is not needed
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# and is ignored)
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cursor.scroll(mode = "last")
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print("LAST ROW")
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print(cursor.fetchone())
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print()
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# scroll to the first row in the result set; the first parameter not needed
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# and is ignored
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cursor.scroll(mode = "first")
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print("FIRST ROW")
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print(cursor.fetchone())
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print()
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# scroll to an absolute row number
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cursor.scroll(5, mode = "absolute")
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print("ROW 5")
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print(cursor.fetchone())
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print()
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# scroll forward six rows (the mode parameter defaults to relative)
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cursor.scroll(3)
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print("SKIP 3 ROWS")
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print(cursor.fetchone())
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print()
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# scroll backward four rows (the mode parameter defaults to relative)
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cursor.scroll(-4)
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print("SKIP BACK 4 ROWS")
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print(cursor.fetchone())
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print()
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