Added a sample demonstrating the use of cursor.lastrowid.

Author: anthony-tuininga

samples/LastRowid.py

@@ -0,0 +1,58 @@
+#------------------------------------------------------------------------------
+# Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+#------------------------------------------------------------------------------
+
+#------------------------------------------------------------------------------
+# LastRowid.py
+#   Demonstrates the use of the cursor.lastrowid attribute.
+#
+# This script requires cx_Oracle 7.3 and higher.
+#------------------------------------------------------------------------------
+
+from __future__ import print_function
+
+import cx_Oracle
+import SampleEnv
+
+connection = cx_Oracle.connect(SampleEnv.GetMainConnectString())
+
+row1 = [1, "First"]
+row2 = [2, "Second"]
+
+# insert a couple of rows and retain the rowid of each
+cursor = connection.cursor()
+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 retained
+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()