16-06-2026 1st commit

src/fact.py

@@ -0,0 +1,41 @@
+from pathlib import Path
+import polars as pl
+from sqlalchemy import Engine
+from datetime import date
+from log import log
+
+
+def fetch_data(
+    engine: Engine,
+    table_name: str,
+    table_type: str,
+    mids: list[int],
+    run_date: date
+) -> pl.DataFrame:
+
+    if not mids:
+        log.warning("No MIDs — nothing to fetch.")
+        return pl.DataFrame()
+
+    mid_list = ",".join(str(mid) for mid in mids)
+
+    sql_file = Path("sql") / table_type / f"{table_name}.sql"
+
+    with open(sql_file, "r", encoding="utf-8") as f:
+        sql_template = f.read()
+
+    sql = sql_template.format(
+        mid_list=mid_list,
+        run_date=run_date.strftime("%Y-%m-%d")
+    )
+
+    log.info(f"Fetching data for {len(mids):,} MIDs")
+
+    df = pl.read_database(
+        query=sql,
+        connection=engine
+    )
+
+    log.info(f"Fetched {len(df):,} rows from SQL Server")
+
+    return df