[NOTICKET] minor code refactor

src/config/settings.py

@@ -63,7 +63,7 @@ class Settings(BaseSettings):
 
     # DB credential encryption (Fernet key for user-registered database creds)
     dataeyond_db_credential_key: str = Field(
-        alias="dataeyond__db__credential__key", default=""
+        alias="dataeyond__db__credential__key"
     )
 
 

src/pipeline/db_pipeline/db_pipeline_service.py

@@ -128,7 +128,7 @@ class DbPipelineService:
             )
             return create_engine(url)
 
-        raise ValueError(f"Unsupported db_type: {db_type}")
+        raise NotImplementedError(f"Unsupported db_type: {db_type}")
 
     @contextmanager
     def engine_scope(

src/pipeline/db_pipeline/extractor.py

@@ -149,10 +149,10 @@ def profile_column(
             order_by="ORDER BY cnt DESC",
         )
         top = pd.read_sql(top_sql, engine)
-        profile["top_values"] = list(zip(top[col_name].tolist(), top["cnt"].tolist()))
+        profile["top_values"] = list(zip(top.iloc[:, 0].tolist(), top["cnt"].tolist()))
 
     sample = pd.read_sql(_head_query(engine, qc, qt, 5), engine)
-    profile["sample_values"] = sample[col_name].tolist()
+    profile["sample_values"] = sample.iloc[:, 0].tolist()
 
     return profile