first commit

internal/database/migrations/20260126093054_create_field_stock.down.sql

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+ALTER TABLE stock_logs
+DROP COLUMN stock;

internal/database/migrations/20260126093054_create_field_stock.up.sql

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+ALTER TABLE stock_logs
+ADD COLUMN stock NUMERIC(15, 3) NOT NULL DEFAULT 0;
+
+WITH calc AS (
+  SELECT
+    id,
+    SUM(COALESCE(increase, 0) - COALESCE(decrease, 0))
+      OVER (
+        PARTITION BY product_warehouse_id
+        ORDER BY id
+        ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+      ) AS running_stock
+  FROM stock_logs
+)
+UPDATE stock_logs t
+SET stock = c.running_stock
+FROM calc c
+WHERE t.id = c.id;
+