Question

我有一个由公司指导员编写的SQL查询，该查询创建了一个包含voucher_Id，procedure TForm1.FormCreate(Sender: TObject); begin AddClearButton(cxDBLookupComboBox1.Properties); end; procedure TForm1.AddClearButton(Prop: TcxCustomEditProperties); begin with Prop.Buttons.Add do begin Kind:= bkText; Caption:= #$2715; //Unicode X-symbol end; Prop.OnButtonClick:= ClearButtonClick; end; procedure TForm1.ClearButtonClick(Sender: TObject; AButtonIndex: Integer); begin if AButtonIndex = 1 then with TcxCustomEdit(Sender) do begin EditValue:= Null; PostEditValue; end; end;，quantity和used列的表，但是，他向我展示了一个示例，需要在我的postgres数据库中并将其写在查询工具内部。我做了一些小的修改，但是当我尝试通过迁移创建实体化视图时，以下查询抛出错误：

这是他在postgres的查询工具中写的查询，它的工作原理像一个超级按钮：

remaining

然后在使用knex进行迁移时，我有：

SELECT v.voucher_id,v.quantity, COUNT(ov.voucher_id) AS "used", v.quantity - COUNT(ov.voucher_id) AS "remaining"
      FROM public.vouchers v
      LEFT OUTER JOIN public.order_vouchers ov ON (v.voucher_id = ov.voucher_id)
      GROUP BY v.voucher_id, v.quantity

该错误专门抛出在CREATE MATERIALIZED VIEW mv_vouchers SELECT * FROM vouchers, SELECT v.voucher_id,v.quantity, COUNT(ov.voucher_id) AS "used", v.quantity - COUNT(ov.voucher_id) AS "left" FROM public.vouchers v LEFT OUTER JOIN public.order_vouchers ov ON (v.voucher_id = ov.voucher_id) GROUP BY v.voucher_id, v.quantity附近，我正在使用的表是SELECT和vouchers。对此我很陌生，非常感谢您的帮助。

Answer 1

您有两个SELECT子句。这就是你想要的吗？

CREATE MATERIALIZED VIEW mv_vouchers as
      SELECT v.voucher_id, v.quantity, COUNT(ov.voucher_id) AS "used", v.quantity - COUNT(ov.voucher_id) AS "left"
      FROM public.vouchers v LEFT OUTER JOIN
           public.order_vouchers ov
           ON v.voucher_id = ov.voucher_id
      GROUP BY v.voucher_id, v.quantity;

使用knex的物化视图迁移错误

1 个答案: