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#------------------------------------------------------------------------------
# Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# array_dml_rowcounts.py
#
# Demonstrate the use of the 12.1 feature that allows cursor.executemany()
# to return the number of rows affected by each individual execution as a list.
# The parameter "arraydmlrowcounts" must be set to True in the call to
# cursor.executemany() after which cursor.getarraydmlrowcounts() can be called.
#
# This script requires cx_Oracle 5.2 and higher.
#------------------------------------------------------------------------------
import cx_Oracle as oracledb
import sample_env
connection = oracledb.connect(sample_env.get_main_connect_string())
cursor = connection.cursor()
# show the number of rows for each parent ID as a means of verifying the
# output from the delete statement
for parent_id, count in cursor.execute("""
select ParentId, count(*)
from ChildTable
group by ParentId
order by ParentId"""):
print("Parent ID:", parent_id, "has", int(count), "rows.")
print()
# delete the following parent IDs only
parent_ids_to_delete = [20, 30, 50]
print("Deleting Parent IDs:", parent_ids_to_delete)
print()
# enable array DML row counts for each iteration executed in executemany()
cursor.executemany("""
delete from ChildTable
where ParentId = :1""",
[(i,) for i in parent_ids_to_delete],
arraydmlrowcounts = True)
# display the number of rows deleted for each parent ID
row_counts = cursor.getarraydmlrowcounts()
for parent_id, count in zip(parent_ids_to_delete, row_counts):
print("Parent ID:", parent_id, "deleted", count, "rows.")
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