fixed support for None as NULL

Author: dmalan

setup.py

@@ -16,5 +16,5 @@
     package_dir={"": "src"},
     packages=["cs50"],
     url="https://github.com/cs50/python-cs50",
-    version="9.2.0"
+    version="9.2.1"
 )

src/cs50/sql.py

@@ -476,7 +476,7 @@ def __escape(value):
             elif value is None:
                 return sqlparse.sql.Token(
                     sqlparse.tokens.Keyword,
-                    sqlalchemy.types.NullType().literal_processor(self._engine.dialect)(value))
+                    sqlalchemy.null())
 
             # Unsupported value
             else:

tests/foo.py

@@ -10,13 +10,15 @@
 logging.getLogger("cs50").disabled = False
 logging.getLogger("cs50").setLevel(logging.ERROR)
 
-db.execute("CREATE TABLE IF NOT EXISTS bar (firstname STRING UNIQUE)")
+db.execute("DROP TABLE IF EXISTS bar")
+db.execute("CREATE TABLE bar (firstname STRING UNIQUE)")
 
-db.execute("INSERT INTO bar VALUES (?)", "baz")
+db.execute("INSERT INTO bar VALUES (?)", None)
 db.execute("INSERT INTO bar VALUES (?)", "baz")
 db.execute("INSERT INTO bar VALUES (?)", "qux")
 db.execute("SELECT * FROM bar WHERE firstname IN (?)", ("baz", "qux"))
-db.execute("DELETE FROM bar")
+print(db.execute("SELECT * FROM bar"))
+#db.execute("DELETE FROM bar")
 
 """