prepare database interaction

prototypes/01_first-look_20260603.py

@@ -1,9 +1,14 @@
 # %%
 import datetime
 import enum
+import json
 from pathlib import Path
+from typing import Any
 
 import polars as pl
+import sqlalchemy as sql
+
+from wattanalyse import db
 
 # %%
 PROJECT_BASE = Path(__file__).parents[1]
@@ -408,6 +413,36 @@ tmp = tmp.with_columns(
     .alias("Durchlaufzeit_Anzahl_Tage"),
 )
 tmp
+
+
+# %%
+# // dump to database
+
+
+def _parse_to_json(value: Any) -> str:
+    if isinstance(value, (datetime.date, datetime.datetime)):
+        return value.isoformat()
+    else:
+        raise TypeError
+
+
+parsed_lists = tmp.with_columns(
+    pl.col(pl.List)
+    .map_elements(
+        lambda x: json.dumps(x.to_list(), default=_parse_to_json) if x is not None else None,
+        return_dtype=pl.String,
+    )
+    .name.keep()
+)
+parsed_lists
+
+
+# %%
+parsed_lists["Import-Ist_Historie"].item(0)
+
+# TODO make UPSERT with staging
+
+########################################################
 # %%
 tmp_1 = tmp.select("Meldezeitpunkt_Historie")
 tmp_1 = tmp_1.with_columns(

prototypes/02_save_to_db.py

@@ -0,0 +1,27 @@
+# %%
+import datetime
+import json
+from typing import Any
+
+# %%
+dt = datetime.datetime.now()
+date = dt.date()
+
+# %%
+val = [dt, date]
+json.dumps(val)
+
+
+# %%
+def _parse_to_json(value: Any) -> str:
+    if isinstance(value, datetime.date):
+        return value.isoformat()
+    elif isinstance(value, datetime.datetime):
+        return value.isoformat()
+    else:
+        raise TypeError
+
+
+# %%
+json.dumps(val, default=_parse_to_json)
+# %%