database

database/migrations/V2__add_unique_index_weather_data.sql

@@ -1,6 +1,21 @@
 -- Flyway V2: Ensure weather_data upsert works by providing a unique index
--- This migration assumes V1 baseline corresponds to the current init.sql schema
+-- Some rows may have been inserted without a uniqueness constraint; de-duplicate first,
+-- keeping the most recently created record per (property_id, date)
 
+-- Remove duplicates (keep latest created_at, then highest id)
+WITH ranked AS (
+  SELECT ctid, ROW_NUMBER() OVER (
+           PARTITION BY property_id, date
+           ORDER BY created_at DESC, id DESC
+         ) AS rn
+  FROM weather_data
+), to_delete AS (
+  SELECT ctid FROM ranked WHERE rn > 1
+)
+DELETE FROM weather_data w
+USING to_delete d
+WHERE w.ctid = d.ctid;
+
+-- Now add the uniqueness guarantee
 CREATE UNIQUE INDEX IF NOT EXISTS ux_weather_data_property_date
   ON weather_data(property_id, date);
-