Fix missing compiler function for ALPHANUM (#214)

Closes #213

CHANGES.rst

@@ -9,6 +9,10 @@ Features
 - Support ``InvalidObjectNameError`` in ``sqlalchemy_hana.errors``
 - Add ``convert_dbapi_error`` to ``sqlalchemy_hana.errors``
 
+Bugfixes
+~~~~~~~~
+- Fixed an issue causing the usage of ALPHANUM to result in an AttributeError
+
 1.2.0
 -----
 

pyproject.toml

@@ -127,7 +127,7 @@ disable = [
 ]
 
 [tool.pylint.basic]
-good-names = ["visit_TINYINT", "visit_SMALLDECIMAL", "visit_SECONDDATE"]
+good-names = ["visit_TINYINT", "visit_SMALLDECIMAL", "visit_SECONDDATE", "visit_ALPHANUM"]
 
 [tool.mypy]
 # formatting

sqlalchemy_hana/dialect.py

@@ -333,6 +333,10 @@ def visit_SECONDDATE(self, type_: types.TypeEngine[Any], **kw: Any) -> str:
         # SAP HANA special type
         return "SECONDDATE"
 
+    def visit_ALPHANUM(self, type_: types.TypeEngine[Any], **kw: Any) -> str:
+        # SAP HANA special type
+        return self._render_string_type(type_, "ALPHANUM")
+
     def visit_string(self, type_: types.TypeEngine[Any], **kw: Any) -> str:
         # Normally string renders as VARCHAR, but we want NVARCHAR
         return self.visit_NVARCHAR(type_, **kw)

test/test_types.py

@@ -12,7 +12,8 @@
 import sqlalchemy
 import sqlalchemy.testing.suite.test_types
 from sqlalchemy import inspect, testing, types
-from sqlalchemy.testing.fixtures import TablesTest
+from sqlalchemy.schema import CreateTable
+from sqlalchemy.testing.fixtures import TablesTest, TestBase
 from sqlalchemy.testing.schema import Column, Table
 from sqlalchemy.testing.suite.test_types import _DateFixture
 
@@ -208,3 +209,14 @@ def reflected_column_type(self):
 class NCLOBTest(_TypeBaseTest):
     column_type = hana_types.NCLOB()
     data = "some test text"
+
+
+class AlphanumTest(TestBase):
+    # no real test possible because ALPHANUM is not supported in SAP HANA Cloud
+
+    def test_compile(self, connection, metadata) -> None:
+        mytab = Table("mytab", metadata, Column("mycol", hana_types.ALPHANUM(10)))
+        assert (
+            str(CreateTable(mytab).compile(connection))
+            == "\nCREATE TABLE mytab (\n\tmycol ALPHANUM(10)\n)\n\n"
+        )