如何从数据存储区返回的对象中检索关键对象 [英] How to retrieve key object from datastore returned object

问题描述

这是一种方法，该方法可以检索用户给定订单ID的所有订单

Here is a method, which retrieves all orders for given order id of the user

func (r *DatastoreRepository) FindOrders(ctx context.Context, userID string, orderIDs []string) ([]*domain.Order, interface{}) {
    keys := make([]*datastore.Key, len(orderIDs))
    for i, orderID := range orderIDs {
        key := datastore.NameKey(kindOrder, orderID, nil)
        key.Namespace = userID
        keys[i] = key
    }

    orders := make([]*domain.Order, len(keys))
    multiErrors := r.client.GetMulti(ctx, keys, orders)

    return orders, multiErrors
}

此方法将 * [] domain.Order 返回给我的服务方法.现在服务方法想要获取给定订单的访问 key 对象(以删除订单).一种方法是根据订单ID为每个订单重新创建密钥，但这听起来像是代码冗余(我也在 FindOrders 中这样做，因此也必须在中这样做以及DeleteOrders ).有没有一种方法可以从 order object 中访问给定订单的 datastore.key 对象?

This method returns *[]domain.Order to my service method. Now service method wants to get access key object of a given order (in order to delete an order). One way to do it is re-create key for every order based on order id but this sounds like a code redundancy (i am doing it in FindOrders as well and would have to do it in DeleteOrders as well). Is there a way that i can access datastore.key object for a given order from order object?

推荐答案

假设 Order 具有一个 ID 字段，只需在元素上循环并设置该字段即可.

Assuming that an Order has an ID field, simply loop over the elements and set the field.

func (r *DatastoreRepository) FindOrders(ctx context.Context, userID string, orderIDs []string) ([]*domain.Order, interface{}) {
    keys := make([]*datastore.Key, len(orderIDs))
    for i, orderID := range orderIDs {
        key := datastore.NameKey(kindOrder, orderID, nil)
        key.Namespace = userID
        keys[i] = key
    }

    orders := make([]*domain.Order, len(keys))
    multiErrors := r.client.GetMulti(ctx, keys, orders)

    // Add this for loop...
    for i, order := range orders {
       order.ID = orderIDs[i]
    }

    return orders, multiErrors
}

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