diff --git a/cumulus_library/log_utils.py b/cumulus_library/log_utils.py
index 2a04be8c..32e32032 100644
--- a/cumulus_library/log_utils.py
+++ b/cumulus_library/log_utils.py
@@ -38,7 +38,7 @@ def log_transaction(
                 __version__,
                 status.value,
                 base_utils.get_utc_datetime(),
-                message if message else None,
+                message or None,
             ]
         ],
     )
diff --git a/cumulus_library/template_sql/insert_into.sql.jinja b/cumulus_library/template_sql/insert_into.sql.jinja
index aca08fef..214bf302 100644
--- a/cumulus_library/template_sql/insert_into.sql.jinja
+++ b/cumulus_library/template_sql/insert_into.sql.jinja
@@ -13,7 +13,7 @@ VALUES
     {%- if table_cols[loop.index0] in type_casts.keys() -%}
     {{ type_casts[table_cols[loop.index0]] }} '{{ field }}'
     {%- elif not field -%}
-    NULL
+    CAST(NULL AS VARCHAR)
     {%- else -%}
     '{{ field }}'
     {%- endif -%}
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 14866f2e..984b80a4 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -85,12 +85,12 @@ def test_cli_early_exit(args):
         (
             ["build", "-t", "study_python_valid", "--builder", "module2"],
             does_not_raise(),
-            "study_python_valid__table_2",
+            "study_python_valid__count_table",
         ),
         (
             ["build", "-t", "study_bad_manifest"],
             pytest.raises(errors.StudyManifestParsingError),
-            "study_python_valid__table_2",
+            "study_python_valid__count_table",
         ),
         (["build", "-t", "wrong"], pytest.raises(SystemExit), None),
         (
@@ -225,6 +225,8 @@ def test_generate_md(mock_path, tmp_path):
             pathlib.Path(__file__).resolve().parent
             / "test_data/study_python_valid_generated.md"
         )
+        with open(test_file) as f:
+            print(f.read())
         assert filecmp.cmp(test_file, ref_file, shallow=True)
 
 
diff --git a/tests/test_data/study_python_valid/manifest.toml b/tests/test_data/study_python_valid/manifest.toml
index d201182b..6509804b 100644
--- a/tests/test_data/study_python_valid/manifest.toml
+++ b/tests/test_data/study_python_valid/manifest.toml
@@ -2,3 +2,8 @@ study_prefix = "study_python_valid"
 
 [table_builder_config]
 file_names = ["module1.py", "module1.py", "module2.py"]
+
+[export_config]
+export_list = [
+    "study_python_valid__count_table"
+]
\ No newline at end of file
diff --git a/tests/test_data/study_python_valid/module2.py b/tests/test_data/study_python_valid/module2.py
index 9ba693c1..a0b8854a 100644
--- a/tests/test_data/study_python_valid/module2.py
+++ b/tests/test_data/study_python_valid/module2.py
@@ -6,5 +6,5 @@ class ModuleTwoRunner(BaseTableBuilder):
 
     def prepare_queries(self, cursor: object, schema: str, *args, **kwargs):
         self.queries.append(
-            "CREATE TABLE IF NOT EXISTS study_python_valid__table_2 (test int);"
+            "CREATE TABLE IF NOT EXISTS study_python_valid__count_table (test int);"
         )
diff --git a/tests/test_data/study_python_valid_generated.md b/tests/test_data/study_python_valid_generated.md
index 2d197279..9335c71b 100644
--- a/tests/test_data/study_python_valid_generated.md
+++ b/tests/test_data/study_python_valid_generated.md
@@ -1,3 +1,12 @@
+## study_python_valid count tables
+
+### study_python_valid__count_table
+
+|Column| Type  |Description|
+|------|-------|-----------|
+|test  |INTEGER|           |
+
+
 ## study_python_valid base tables
 
 ### study_python_valid__lib_transactions
@@ -18,10 +27,3 @@
 |test  |INTEGER|           |
 
 
-### study_python_valid__table_2
-
-|Column| Type  |Description|
-|------|-------|-----------|
-|test  |INTEGER|           |
-
-