保留新行的前一行数据 - Keep data from previous row for new row

Keep data from previous row for new row

本文关键字：一行数据新行保留 | 更新日期: 2023-09-27

我有一个类似这样的表：

    VIN         Color  Tires      Mileage
    -------------------------------------
    (car's VIN) red    P235/70R15 32976

If I do body work and change the color, change the tires, or the mileage changes while testing a repair, I want to be able to keep all of the unchanged fields (color, tires) from the previous row while inserting the new row with the new mileage.

I need to keep the existing row.

How can I use PHP and MySQL to accomplish this?

You need to use a parent/child relationship. Here's an example with required columns to work:

ID parent_id    VIN        Color   Tires        Mileage
-------------------------------------------------------
1  NULL         (car's vin) red    P235/70R15   32976
2  1            ''          blue   P235/70R15   35017

请注意，您正在确定ID 2是ID 1的子级，并具有更新的信息。

您只需创建一个walker函数来拉取父和子之间的关系