七月迭代短暂完结,还有很多后端的关键东西没有弄,这是一版赶时间做的东西

migrations/000191_add_refund_approval_instance.up.sql

@@ -0,0 +1,20 @@
+-- 为退款申请关联唯一通用审批实例。
+ALTER TABLE tb_refund_request
+    ADD COLUMN IF NOT EXISTS approval_instance_id bigint;
+
+CREATE UNIQUE INDEX IF NOT EXISTS uq_refund_request_approval_instance
+    ON tb_refund_request (approval_instance_id)
+    WHERE approval_instance_id IS NOT NULL;
+
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1 FROM pg_constraint WHERE conname = 'chk_refund_request_approval_instance'
+    ) THEN
+        ALTER TABLE tb_refund_request
+            ADD CONSTRAINT chk_refund_request_approval_instance
+            CHECK (approval_instance_id IS NULL OR approval_instance_id > 0);
+    END IF;
+END $$;
+
+COMMENT ON COLUMN tb_refund_request.approval_instance_id IS '退款申请关联的唯一通用审批实例 ID，存量旧审批记录为空';