71 lines
2.2 KiB
Python
71 lines
2.2 KiB
Python
#------------------------------------------------------------------------------
|
|
# Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
|
|
#
|
|
# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
|
|
#
|
|
# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
|
|
# Canada. All rights reserved.
|
|
#------------------------------------------------------------------------------
|
|
|
|
#------------------------------------------------------------------------------
|
|
# scrollable_cursors.py
|
|
# This script demonstrates how to use scrollable cursors. These allow moving
|
|
# forward and backward in the result set but incur additional overhead on the
|
|
# server to retain this information.
|
|
#
|
|
# This script requires cx_Oracle 5.3 and higher.
|
|
#------------------------------------------------------------------------------
|
|
|
|
import cx_Oracle as oracledb
|
|
import sample_env
|
|
|
|
connection = oracledb.connect(sample_env.get_main_connect_string())
|
|
|
|
# show all of the rows available in the table
|
|
cursor = connection.cursor()
|
|
cursor.execute("select * from TestStrings order by IntCol")
|
|
print("ALL ROWS")
|
|
for row in cursor:
|
|
print(row)
|
|
print()
|
|
|
|
# create a scrollable cursor
|
|
cursor = connection.cursor(scrollable = True)
|
|
|
|
# set array size smaller than the default (100) to force scrolling by the
|
|
# database; otherwise, scrolling occurs directly within the buffers
|
|
cursor.arraysize = 3
|
|
cursor.execute("select * from TestStrings order by IntCol")
|
|
|
|
# scroll to last row in the result set; the first parameter is not needed and
|
|
# is ignored)
|
|
cursor.scroll(mode = "last")
|
|
print("LAST ROW")
|
|
print(cursor.fetchone())
|
|
print()
|
|
|
|
# scroll to the first row in the result set; the first parameter not needed and
|
|
# is ignored
|
|
cursor.scroll(mode = "first")
|
|
print("FIRST ROW")
|
|
print(cursor.fetchone())
|
|
print()
|
|
|
|
# scroll to an absolute row number
|
|
cursor.scroll(5, mode = "absolute")
|
|
print("ROW 5")
|
|
print(cursor.fetchone())
|
|
print()
|
|
|
|
# scroll forward six rows (the mode parameter defaults to relative)
|
|
cursor.scroll(3)
|
|
print("SKIP 3 ROWS")
|
|
print(cursor.fetchone())
|
|
print()
|
|
|
|
# scroll backward four rows (the mode parameter defaults to relative)
|
|
cursor.scroll(-4)
|
|
print("SKIP BACK 4 ROWS")
|
|
print(cursor.fetchone())
|
|
print()
|