gh-93421: Update sqlite3 cursor.rowcount after SQLITE_DONE

Lib/test/test_sqlite3/test_dbapi.py

@@ -898,6 +898,14 @@ def test_rowcount_executemany(self):
  self.cu.executemany("insert into test(name) values (?)", [(1,), (2,), (3,)])
  self.assertEqual(self.cu.rowcount, 3)
 
+ @unittest.skipIf(sqlite.sqlite_version_info < (3, 35, 0),
+ "Requires SQLite 3.35.0 or newer")
+ def test_rowcount_update_returning(self):
+ # gh-93421: rowcount is updated correctly for UPDATE...RETURNING queries
+ self.cu.execute("update test set name='bar' where name='foo' returning 1")
+ self.assertEqual(self.cu.fetchone()[0], 1)
+ self.assertEqual(self.cu.rowcount, 1)
+
  def test_total_changes(self):
  self.cu.execute("insert into test(name) values ('foo')")
  self.cu.execute("insert into test(name) values ('foo')")

Misc/NEWS.d/next/Library/2022-06-05-22-22-42.gh-issue-93421.43UO_8.rst

@@ -0,0 +1,3 @@
+Update :data:`sqlite3.Cursor.rowcount` when a DML statement has run to
+completion. This fixes the row count for SQL queries like
+``UPDATE ... RETURNING``. Patch by Erlend E. Aasland.

Modules/_sqlite/cursor.c

@@ -835,10 +835,9 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* operation
  stmt_reset(self->statement);
  }
 
- /* reset description and rowcount */
+ /* reset description */
  Py_INCREF(Py_None);
  Py_SETREF(self->description, Py_None);
- self->rowcount = 0L;
 
  if (self->statement) {
  (void)stmt_reset(self->statement);
@@ -867,6 +866,7 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* operation
 
  stmt_reset(self->statement);
  stmt_mark_dirty(self->statement);
+ self->rowcount = self->statement->is_dml ? 0L : -1L;
 
  /* We start a transaction implicitly before a DML statement.
  SELECT is the only exception. See #9924. */
@@ -944,18 +944,18 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* operation
  }
  }
 
- if (self->statement->is_dml) {
- self->rowcount += (long)sqlite3_changes(self->connection->db);
- } else {
- self->rowcount= -1L;
- }
-
  if (rc == SQLITE_DONE && !multiple) {
+ if (self->statement->is_dml) {
+ self->rowcount = (long)sqlite3_changes(self->connection->db);
+ }
  stmt_reset(self->statement);
  Py_CLEAR(self->statement);
  }
 
  if (multiple) {
+ if (self->statement->is_dml && rc == SQLITE_DONE) {
+ self->rowcount += (long)sqlite3_changes(self->connection->db);
+ }
  stmt_reset(self->statement);
  }
  Py_XDECREF(parameters);
@@ -1125,6 +1125,9 @@ pysqlite_cursor_iternext(pysqlite_Cursor *self)
  }
  int rc = stmt_step(stmt);
  if (rc == SQLITE_DONE) {
+ if (self->statement->is_dml) {
+ self->rowcount = (long)sqlite3_changes(self->connection->db);
+ }
  (void)stmt_reset(self->statement);
  }
  else if (rc != SQLITE_ROW) {