Add SQLAlchemy and database boilerplate code

tofu_api/common/database/metadata.py

@@ -0,0 +1,17 @@
+from sqlalchemy import MetaData
+
+__all__ = [
+    'metadata_obj',
+]
+
+# Define naming convention for constraints
+_naming_convention = {
+    "ix": 'ix_%(column_0_label)s',
+    "uq": "uq_%(table_name)s_%(column_0_name)s",
+    "ck": "ck_%(table_name)s_%(constraint_name)s",
+    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
+    "pk": "pk_%(table_name)s"
+}
+
+# Create global metadata object for database schemas
+metadata_obj = MetaData(naming_convention=_naming_convention)