fix issue

apps/edr-freight-api/src/migrations/2280000000000-WagonNumberPartialUnique.ts

@@ -0,0 +1,70 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Wagons are now soft-deleted (deleted_at) instead of hard-deleted. The plain
+ * UNIQUE on wagon_number would keep a retired wagon's number reserved forever
+ * and block ever re-registering that number. Swap it for a PARTIAL unique index
+ * that only constrains live rows (deleted_at IS NULL); soft-deleted wagons no
+ * longer occupy their number.
+ *
+ * NOTE: the shared dev DB has no applied migration history, so this is also
+ * hand-applied there. The DO blocks + IF EXISTS/IF NOT EXISTS keep it
+ * idempotent whether the original uniqueness is the auto-named column
+ * constraint (wagons_wagon_number_key) or a TypeORM-named UQ_* constraint/index.
+ */
+export class WagonNumberPartialUnique2280000000000 implements MigrationInterface {
+  name = 'WagonNumberPartialUnique2280000000000';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    // Drop any UNIQUE constraint on freight.wagons(wagon_number), whatever it is
+    // named (dropping the constraint also drops its backing index).
+    await queryRunner.query(`
+      DO $$
+      DECLARE con_name text;
+      BEGIN
+        FOR con_name IN
+          SELECT conname
+            FROM pg_constraint
+           WHERE conrelid = 'freight.wagons'::regclass
+             AND contype = 'u'
+             AND pg_get_constraintdef(oid) ILIKE '%(wagon_number)%'
+        LOOP
+          EXECUTE format('ALTER TABLE freight.wagons DROP CONSTRAINT IF EXISTS %I', con_name);
+        END LOOP;
+      END $$;
+    `);
+
+    // Drop any standalone (non-partial) unique index on wagon_number too.
+    await queryRunner.query(`
+      DO $$
+      DECLARE idx_name text;
+      BEGIN
+        FOR idx_name IN
+          SELECT c.relname
+            FROM pg_index i
+            JOIN pg_class c ON c.oid = i.indexrelid
+           WHERE i.indrelid = 'freight.wagons'::regclass
+             AND i.indisunique
+             AND i.indpred IS NULL
+             AND c.relname <> 'UQ_wagons_wagon_number_active'
+             AND pg_get_indexdef(i.indexrelid) ILIKE '%(wagon_number)%'
+        LOOP
+          EXECUTE format('DROP INDEX IF EXISTS freight.%I', idx_name);
+        END LOOP;
+      END $$;
+    `);
+
+    // Live wagon numbers stay unique; soft-deleted rows are exempt.
+    await queryRunner.query(`
+      CREATE UNIQUE INDEX IF NOT EXISTS "UQ_wagons_wagon_number_active"
+        ON freight.wagons (wagon_number)
+        WHERE deleted_at IS NULL;
+    `);
+  }
+
+  public async down(): Promise<void> {
+    // No-op: re-adding a plain UNIQUE would fail whenever two soft-deleted
+    // wagons share a number, and the partial index is strictly safer. Left in
+    // place intentionally.
+  }
+}