feat: additional expenses

services/statistics/common.py

@@ -0,0 +1,19 @@
+from datetime import date
+
+from sqlalchemy import select, func, literal, text, cast, CTE
+from sqlalchemy.dialects.postgresql import TIMESTAMP
+
+
+def generate_date_range(date_from: date, date_to: date, additional_columns: list[str]) -> CTE:
+    cols = [literal(0).label(col_label) for col_label in additional_columns]
+    return select(
+        cast(
+            func.generate_series(
+                date_from,
+                date_to,
+                text("'1 day'")
+            ),
+            TIMESTAMP(timezone=False)
+        ).label("date"),
+        *cols,
+    ).cte()