python-oracledb/samples/last_rowid.py

83 lines
3.2 KiB
Python

#------------------------------------------------------------------------------
# Copyright (c) 2019, 2022, 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.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# last_rowid.py
#
# Demonstrates the use of the cursor.lastrowid attribute.
#------------------------------------------------------------------------------
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())
connection = oracledb.connect(user=sample_env.get_main_user(),
password=sample_env.get_main_password(),
dsn=sample_env.get_connect_string())
with connection.cursor() as cursor:
# insert a couple of rows and retain the rowid of each
row1 = [1, "First"]
row2 = [2, "Second"]
cursor.execute("insert into mytab (id, data) values (:1, :2)", row1)
rowid1 = cursor.lastrowid
print("Row 1:", row1)
print("Rowid 1:", rowid1)
print()
cursor.execute("insert into mytab (id, data) values (:1, :2)", row2)
rowid2 = cursor.lastrowid
print("Row 2:", row2)
print("Rowid 2:", rowid2)
print()
# the row can be fetched with the rowid that was returned
cursor.execute("select id, data from mytab where rowid = :1", [rowid1])
print("Row 1:", cursor.fetchone())
cursor.execute("select id, data from mytab where rowid = :1", [rowid2])
print("Row 2:", cursor.fetchone())
print()
# updating multiple rows only returns the rowid of the last updated row
cursor.execute("update mytab set data = data || ' (Modified)'")
cursor.execute("select id, data from mytab where rowid = :1",
[cursor.lastrowid])
print("Last updated row:", cursor.fetchone())
# deleting multiple rows only returns the rowid of the last deleted row
cursor.execute("delete from mytab")
print("Rowid of last deleted row:", cursor.lastrowid)
# deleting no rows results in a value of None
cursor.execute("delete from mytab")
print("Rowid when no rows are deleted:", cursor.lastrowid)
# Don't commit - this lets us run the demo multiple times
#connection.commit()