Firebase - 在对多个节点进行更新/扇出时设置优先级 [英] Firebase - set priority when doing an update/fanout to several nodes

问题描述

我正在一次更新中写入Firebase数据库的多个部分/节点。这样做时可以设置节点的优先级吗？例子：

pre $ firebaseRef.update（
/ some / node /：value，
/ some / other / node：other value
]）

如果我想同时在/ some / other / node设置节点的优先级。那可能吗？例如：

  firebaseRef.update（[
/ some / node /：value，
/ some / other / node：{
 value：other value，
 priority：0  -  Date.now（）
} 
]）
  

解决方案

你几乎知道了，magic属性被命名为 .priority ：

  firebaseRef.update（[
/ some / node /：value，
/ some / other / node：{
 value：other value，
.priority：0  -  Date.now（） 
 
 
 
 
 $ b $ p $注意到并没有太多的原因（如reversedTimestamp：0  -  Date.now（））将会完成相同的操作，隐藏/魔法也会减少。  
 
 
更新
 
 
 
看来你想要更新节点的值，而不是一个名为value的子节点。 （原始）价值和优先权，使用：
 
 pre $ firebaseRef.update（
/ some / node /：value，
/ some / other / node：{
.value：other value，
.priority：0  -  Date.now（）
} 
]）; 
  

I'm writing to several parts/nodes of my Firebase database in one update. Is it possible to set the priority of a node when doing this? Example:

firebaseRef.update([
    "/some/node/": "value",
    "/some/other/node": "other value"
])

What if I want to set the priority of the node at "/some/other/node" at the same time. Is that possible? Something like:

firebaseRef.update([
    "/some/node/": "value",
    "/some/other/node": {
        value: "other value",
        priority:  0 - Date.now()
    }
])

解决方案

You almost got it, the "magic" property is named .priority:

firebaseRef.update([
    "/some/node/": "value",
    "/some/other/node": {
        value: "other value",
        ".priority":  0 - Date.now()
    }
]

Note that there aren't really a lot of reasons to use priorities anymore in Firebase. Adding a normally named property (e.g. "reversedTimestamp": 0 - Date.now()) will accomplish the same and is less hidden/magic.

Update

It seems you want to update the node's value, not a child named value. To set the (primitive) value and priority in one go, use:

firebaseRef.update([
    "/some/node/": "value",
    "/some/other/node": {
        ".value": "other value",
        ".priority":  0 - Date.now()
    }
]);

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