fetchall and fetchmany will returns empty list with no rows (#1028)

Signed-off-by: Balram Choudhary <bchoudhary@rocketsoftware.com>

Author: bchoudhary6415

ibm_db.c

@@ -17328,9 +17328,9 @@ static PyObject *ibm_db_fetchmany(PyObject *self, PyObject *args)
     }
     if (PyList_Size(result_list) == 0)
     {
-        LogMsg(DEBUG, "No rows fetched, returning None");
-        Py_XDECREF(result_list);
-        Py_RETURN_NONE;
+        LogMsg(DEBUG, "No rows fetched, returning empty list");
+        LogMsg(INFO, "exit fetchmany()");
+        return result_list;
     }
     snprintf(messageStr, sizeof(messageStr), "Returning %zd rows", PyList_Size(result_list));
     LogMsg(DEBUG, messageStr);
@@ -17376,9 +17376,9 @@ static PyObject *ibm_db_fetchall(PyObject *self, PyObject *args)
     }
     if (PyList_Size(result_list) == 0)
     {
-        LogMsg(DEBUG, "No rows fetched, returning None");
-        Py_XDECREF(result_list);
-        Py_RETURN_NONE;
+        LogMsg(DEBUG, "No rows fetched, returning empty list");
+        LogMsg(INFO, "exit fetchall()");
+        return result_list;
     }
     snprintf(messageStr, sizeof(messageStr), "Returning %zd rows", PyList_Size(result_list));
     LogMsg(DEBUG, messageStr);

ibm_db_tests/test_319_FetchMethods_DBI.py

@@ -0,0 +1,91 @@
+#
+#  Licensed Materials - Property of IBM
+#
+#  (c) Copyright IBM Corp. 2025
+#
+
+from __future__ import print_function
+import sys
+import unittest
+import ibm_db
+import ibm_db_dbi
+import config
+from testfunctions import IbmDbTestFunctions
+
+
+class IbmDbTestCase(unittest.TestCase):
+
+    def test_319_FetchMethods_DBI(self):
+        obj = IbmDbTestFunctions()
+        obj.assert_expect(self.run_test_319)
+
+    def run_test_319(self):
+        conn = ibm_db.connect(config.database, config.user, config.password)
+
+        ibm_db.autocommit(conn, ibm_db.SQL_AUTOCOMMIT_OFF)
+
+        dbi_conn = ibm_db_dbi.Connection(conn)
+
+        # Drop the test table, in case it exists
+        drop = 'DROP TABLE dbiEmployees'
+        try:
+            cur = dbi_conn.cursor()
+            cur.execute(drop)
+        except:
+            pass
+
+        # Create the test table
+        create = 'CREATE TABLE dbiEmployees (id INT PRIMARY KEY NOT NULL, name VARCHAR(255), age INT)'
+        cur = dbi_conn.cursor()
+        cur.execute(create)
+
+        # Insert rows into the table
+        insert_sql = 'INSERT INTO dbiEmployees (id, name, age) VALUES (?, ?, ?)'
+        employees = [
+            (1, 'Alice', 30),
+            (2, 'Bob', 24),
+            (3, 'Charlie', 29),
+            (4, 'Diana', 35),
+            (5, 'Eve', 40)
+        ]
+        for emp in employees:
+            cur.execute(insert_sql, emp)
+
+        dbi_conn.commit()
+
+        # 1) fetchone example
+        cur1 = dbi_conn.cursor()
+        cur1.execute('SELECT * FROM dbiEmployees ORDER BY id')
+        row = cur1.fetchone()
+        print("fetchone():", row)
+
+        # 2) fetchmany example
+        cur2 = dbi_conn.cursor()
+        cur2.execute('SELECT * FROM dbiEmployees ORDER BY id')
+        rows = cur2.fetchmany(2)
+        print("fetchmany(2):", rows)
+
+        # 3) fetchall example
+        cur3 = dbi_conn.cursor()
+        cur3.execute('SELECT * FROM dbiEmployees ORDER BY id')
+        all_rows = cur3.fetchall()
+        print("fetchall():", all_rows)
+
+#__END__
+#__LUW_EXPECTED__
+#fetchone(): (1, 'Alice', 30)
+#fetchmany(2): [(1, 'Alice', 30), (2, 'Bob', 24)]
+#fetchall(): [(1, 'Alice', 30), (2, 'Bob', 24), (3, 'Charlie', 29), (4, 'Diana', 35), (5, 'Eve', 40)]
+#__ZOS_EXPECTED__
+#fetchone(): (1, 'Alice', 30)
+#fetchmany(2): [(1, 'Alice', 30), (2, 'Bob', 24)]
+#fetchall(): [(1, 'Alice', 30), (2, 'Bob', 24), (3, 'Charlie', 29), (4, 'Diana', 35), (5, 'Eve', 40)]
+#__SYSTEMI_EXPECTED__
+#fetchone(): (1, 'Alice', 30)
+#fetchmany(2): [(1, 'Alice', 30), (2, 'Bob', 24)]
+#fetchall(): [(1, 'Alice', 30), (2, 'Bob', 24), (3, 'Charlie', 29), (4, 'Diana', 35), (5, 'Eve', 40)]
+#__IDS_EXPECTED__
+#fetchone(): (1, 'Alice', 30)
+#fetchmany(2): [(1, 'Alice', 30), (2, 'Bob', 24)]
+#fetchall(): [(1, 'Alice', 30), (2, 'Bob', 24), (3, 'Charlie', 29), (4, 'Diana', 35), (5, 'Eve', 40)]
+

ibm_db_tests/test_320_EmptyFetchMethods_DBI.py

@@ -0,0 +1,78 @@
+#
+#  Licensed Materials - Property of IBM
+#
+#  (c) Copyright IBM Corp. 2025
+#
+
+from __future__ import print_function
+import sys
+import unittest
+import ibm_db
+import ibm_db_dbi
+import config
+from testfunctions import IbmDbTestFunctions
+
+
+class IbmDbTestCase(unittest.TestCase):
+
+    def test_320_EmptyFetchMethods_DBI(self):
+        obj = IbmDbTestFunctions()
+        obj.assert_expect(self.run_test_320)
+
+    def run_test_320(self):
+        conn = ibm_db.connect(config.database, config.user, config.password)
+
+        ibm_db.autocommit(conn, ibm_db.SQL_AUTOCOMMIT_OFF)
+
+        dbi_conn = ibm_db_dbi.Connection(conn)
+
+        # Drop the test table, if exists
+        drop = 'DROP TABLE dbiEmployeesEmpty'
+        try:
+            cur = dbi_conn.cursor()
+            cur.execute(drop)
+        except:
+            pass
+
+        # Create the test table (empty)
+        create = 'CREATE TABLE dbiEmployeesEmpty (id INT PRIMARY KEY NOT NULL, name VARCHAR(255), age INT)'
+        cur = dbi_conn.cursor()
+        cur.execute(create)
+
+        dbi_conn.commit()
+
+        # 1) fetchone example on empty table
+        cur1 = dbi_conn.cursor()
+        cur1.execute('SELECT * FROM dbiEmployeesEmpty ORDER BY id')
+        row = cur1.fetchone()
+        print("fetchone():", row)
+
+        # 2) fetchmany example on empty table
+        cur2 = dbi_conn.cursor()
+        cur2.execute('SELECT * FROM dbiEmployeesEmpty ORDER BY id')
+        rows = cur2.fetchmany(2)
+        print("fetchmany(2):", rows)
+
+        # 3) fetchall example on empty table
+        cur3 = dbi_conn.cursor()
+        cur3.execute('SELECT * FROM dbiEmployeesEmpty ORDER BY id')
+        all_rows = cur3.fetchall()
+        print("fetchall():", all_rows)
+
+#__END__
+#__LUW_EXPECTED__
+#fetchone(): None
+#fetchmany(2): []
+#fetchall(): []
+#__ZOS_EXPECTED__
+#fetchone(): None
+#fetchmany(2): []
+#fetchall(): []
+#__SYSTEMI_EXPECTED__
+#fetchone(): None
+#fetchmany(2): []
+#fetchall(): []
+#__IDS_EXPECTED__
+#fetchone(): None
+#fetchmany(2): []
+#fetchall(): []