How to retreive or calculate minimum and maximum values from data after parse JSON

[Anonymous]

I am bulding a flow which retrieves a .json. (http action GET)
This .json contains 24 items. 
One of the values in these 24 items is the temperature data from a wheaterstation.
With the Parse Json I am able to convert the data to html, csv or use select from the Data Operations actions.
As an example the result from the select action in my flow:

From the 24 temperature values I want to determine the minimum and maximum temperature (and write them to a Sharepoint list). I have tried several suggested solutions to retrieve the minimum and maximum value, however did not succeed in finding a working solution. Perhaps I am looking for the wrong solutions, search terms etc.

 
What have i tried :

https://powerusers.microsoft.com/t5/Building-Flows/Convert-array-to-string/td-p/79125

https://powerusers.microsoft.com/t5/Building-Flows/How-to-get-value-of-array-from-a-JSON-Object-usin...

https://powerusers.microsoft.com/t5/Building-Flows/How-to-access-JSON-Array-items/td-p/83265

Resulting in errors as non supported types (float or string) etc. 

Maybe one of you could point me in the right direction?

[Pieter_Veenstra]

The easiest way is probably just to use actions that set variables within an Apply to Each step.

So within the Apply to each use a condition to thet the loweest value, the highest value to keep the total and keep a counter.

Then after the Apply to each calculate the average.

[v-xida-msft · Accepted solution]

Hi @Anonymous,

Could you please share a full screenshot of your flow's configuration?

I agree with @Pieter_Veenstra's thought almost, I have made a test on my side and please take a try with the following workaround:

• Add a proper trigger, here I use Flow Button trigger.
• Add a Compose action, Inputs set to following json data that you mentioned:

[
  {
    "time": "2018-04-04T00:00:00",
    "temperature": 8.7,
    "relativeHumidity": 98,
    "rainPastHour": 5.3
  },
  {
    "time": "2018-04-05T00:00:00",
    "temperature": 8.8,
    "relativeHumidity": 98,
    "rainPastHour": 5.3
  },
  {
    "time": "2018-04-06T00:00:00",
    "temperature": 12,
    "relativeHumidity": 98,
    "rainPastHour": 5.3
  },
  {
    "time": "2018-04-07T00:00:00",
    "temperature": 10,
    "relativeHumidity": 98,
    "rainPastHour": 5.3
  },
  {
    "time": "2018-04-08T00:00:00",
    "temperature": 6.1,
    "relativeHumidity": 98,
    "rainPastHour": 5.3
  }
]

• Add a "Select" action, From set to output of "Compose" action. Within Map entry, type one entry. Name set to Temp and Value set to following formula:

item()?['temperature']

• Add a Variables-> "Initialize variable" action, Name set to MaximunValue, Type set to Float and Value set to following formula:

first(body('Select'))?['Temp']

• Add a Variables-> "Initialize variable" action, Name set to MinimumValue, Type set to Float and Value set to following formula:

first(body('Select'))?['Temp']

• Add a parallel branch action, within left branch, add a "Apply to each" action, Input parameter set to output of "Select" action. Wihtin "Apply to each" action, add a Condition, Click "Edit in advanced mode", type the following formula:

@greater(item()?['Temp'], variables('MaximunValue'))

Within "If/yes" branch of Condition, add a "Set variable" action, Name set to MaximunValue, Value set to following formula:

item()?['Temp']

Within right branch, add a "Apply to each 2" action, Input parameter set to output of "Select" action. Wihtin "Apply to each" action, add a Condition, Click "Edit in advanced mode", type the following formula:

@less(item()?['Temp'], variables('MinimumValue'))

Within "If/yes" branch of Condition, add a "Set variable" action, Name set to MinimumValue, Value set to following formula:

item()?['Temp']

• Under the Parallel branch action, add a Compose action, Inputs set to MaximunValue variable and MinimumValue variable.

Image reference:

The flow works successfullly as below:

More details about using expression in flow actions, please check the following article:

Using expression in flow actions

More details about Parallel Branch action in Microsoft Flow, please check the following article:

https://flow.microsoft.com/en-us/blog/parallel-actions/

Best regards,

Kris

[Meneghino]

Hi all, I find it difficult to believe that the max() expression cannot be used in this case.

Could @v-micsh-msft or @yoshihirok or anyone else confirm that max() cannot be used and that a loop with for each has to be used?

I have exactly the same situation/question as @Anonymous