过滤查询中的Logic App绕过Null [英] Logic App bypass Null in filter query

问题描述

我正在构建一个使用Azure资源连接器的逻辑应用程序，以获取我的资源列表.然后，我想将结果过滤到标签名称为stop和normal的Microsoft.Compute资源中.

I am building a Logic App that uses the Azure Resource connector to obtain a list of my resources. I would then like to filter the results to Microsoft.Compute resources that have a tag name and value of stop and normal.

以下是我收到的资源摘要，没有任何过滤器

Here is a snippet of resource that I receive back without any filters

{
    "id": "/subscriptions/<subscription>/resourceGroups/Env1/providers/Microsoft.Compute/virtualMachines/MyVM1",
    "name": "MyVM1",
    "type": "Microsoft.Compute/virtualMachines",
    "location": "westeurope",
    "tags": {
        "stop": "normal"
    }
},
{
    "id": "/subscriptions/<subscription>/resourceGroups/LogicApp/providers/Microsoft.Logic/workflows/DWSize-Check",
    "name": "DWSize-Check",
    "type": "Microsoft.Logic/workflows",
    "location": "westeurope",
    "tags": {}
}

如您所见，底部资源不包含任何标签，就像列表中将出现的许多其他标签一样.

As you can see, the bottom resource does not contain any tags, as with many others that will appear in the list

我使用标准的Compose Filter Array连接器尝试从收到的value中过滤掉.

I use the standard Compose Filter Array connector to try and filter out from the value I receive back.

这是我希望用于filter命令的代码:

Here is the code that I wish to use for the filter command:

@and(contains(item()?['id'], '/Microsoft.Compute/virtualMachines/'), contains(item()?['tags'], variables('TagName')), contains(item()?['tags'], variables('TagValue')))

variables('TagName')和variables('TagValue')分别是stop和normal，如我的结果摘要中列出的示例标记所示.

variables('TagName') and variables('TagValue') will be stop and normal, as show in the example tags listed in my results snippet.

但是，由于在其他资源(例如Microsoft.Logic/workflows)中没有列出标签值，因此出现以下null错误:

However, because there is no tag values listed in other resources, such as Microsoft.Logic/workflows, I receive the following null error:

InvalidTemplate.模板动作"Filter_array"的执行 失败:对查询"操作何处"表达式的求值 '@contains(item()?['tags']，variables('TagValue'))''失败:' 模板语言函数包含"期望其第一个参数 集合"可以是字典(对象)，数组或字符串.这 提供的值的类型为'Null'.

InvalidTemplate. The execution of template action 'Filter_array' failed: The evaluation of 'query' action 'where' expression '@contains(item()?['tags'], variables('TagValue'))' failed: 'The template language function 'contains' expects its first argument 'collection' to be a dictionary (object), an array or a string. The provided value is of type 'Null'.'.

有人知道如何解决这个问题吗?

Would anyone know how to get around this?

我曾尝试与此@contains(item().tags?.stop, variables('TagValue'))类似的查询，只是看它是否拾取了任何东西，但我仍然被null响应阻止:(

I have tried similar queries to this @contains(item().tags?.stop, variables('TagValue')) just to see if it picks up anything, but I'm still blocked by a null response :(

我在

I tried the above with the help of the Workflow Definition Language, but still no dice. Any help would be greatly appreciated.

编辑

除了托马斯(Thomas)发布的答案外，我还执行了以下操作(下图)，从结果中过滤出null并转到TagName，但是我仍然无法访问TagValue ，即使我使用包含:

In addition to the answer posted by Thomas, I have performed the following (image below) to filter out null from the results and get to the TagName, but I am still unable to get to the TagValue, even if I use contains:

@and(contains(item()?['tags'], variables('TagName')), contains(item()?['tags'], variables('TagValue')))

或仅尝试查找TagValue

@contains(item()?['tags'], variables('TagValue'))

推荐答案

您可以检查null并返回一个空值(在您的情况下为一个空数组).

You can check for null and return an empty value (an empty array in your case).

您可以用此表达式替换item()?['tags']或创建一个变量:

You can replace item()?['tags'] with this expression or create a variable :

if(equals(item()?['tags'], null), [], item()?['tags'])

这篇关于过滤查询中的Logic App绕过Null的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！