update expense item name

migrations/000072_add_expense_name_to_expenses.down.sql

@@ -1,2 +1,16 @@
-DROP INDEX IF EXISTS idx_expenses_expense_name;
-ALTER TABLE expenses DROP COLUMN expense_name;
+ALTER TABLE expenses ADD COLUMN IF NOT EXISTS expense_name VARCHAR(255) NOT NULL DEFAULT '';
+
+UPDATE expenses e
+SET expense_name = first_item.item
+FROM (
+    SELECT DISTINCT ON (expense_id) expense_id, item
+    FROM expense_items
+    WHERE COALESCE(item, '') != ''
+    ORDER BY expense_id, created_at ASC
+) first_item
+WHERE e.id = first_item.expense_id
+  AND COALESCE(e.expense_name, '') = '';
+
+CREATE INDEX IF NOT EXISTS idx_expenses_expense_name ON expenses(expense_name);
+DROP INDEX IF EXISTS idx_expense_items_item;
+ALTER TABLE expense_items DROP COLUMN IF EXISTS item;