Merging two Arrays of objects

[Anonymous]

Hi

I am trying to merge two arrays of objects to one array.
The two arrays have one property in common that should be used to correlate the data correctly.
The arrays are not sorted in order and have different number of objects.

How do I combine the two arrays into to a single array with three properties using the ID property to correlate them correctly?

Br Martin Strandholm

Array 1:

[
{
"ID": "3333",
"Object_Name": "Power"
},
{
"ID": "1111",
"Object_Name": "Automate"
},
{
"ID": "2222",
"Object_Name": "Function"
}
]

Array 2:

[
{
"ID": "1111",
"Size": "5"
},
{
"ID": "2222",
"Size": "6"
},
{
"ID": "3333",
"Size": "8"
},

{
"ID": "4444",
"Size": "8"
}
]

[ManishJain]

Hi @Anonymous ,

Here is a nice article written for the same :

https://sharepains.com/2020/03/20/create-joins-in-power-automate/

Thanks

[Paulie78 · Accepted solution]

Hi @Anonymous,

It is an interesting question and something that comes up quite often. I've done a video for you which demonstrates a very efficient way of performing what you want to do.

https://youtu.be/QSF6dNkSKSA

Hope it helps.

Blog: tachytelic.net

YouTube: https://www.youtube.com/c/PaulieM/videos

If I answered your question, please accept it as a solution 😘

[Anonymous]

Thank you Paulie78.

I was trying with different ways of getting this done with good performance since the input will be a sharepoint list with a few thousand objects being combined with input from excel with about 600 objects.
When I tried doing it with Apply to each inside Apply to each it takes forever.

The way you did it was very clever and I will try to get it working.

Br Martin Strandholm

[Anonymous]

Hello

It is working nicely, except when one of the arrays is missing the id value.
Is there a way for the merge compose action to accept a null value in ID and continue?
Just adding the property accepting that the item()['ID'] is null?

addProperty(item(), 'Size', xpath(outputs('XML'), concat('//Array[ID/text()="', item()['ID'], '"]/Size/text()'))[0]) 

[Paulie78]

Change the expression to:

addProperty(item(), 'Size', xpath(outputs('XML'), concat('//Array[ID/text()="', item()?['ID'], '"]/Size/text()'))?[0])

[svivek]

Hi,

I applied above solution in my case which is:

I need to merge following arrays:

Array 1:

[

  {

    "Parameter": "2A",

    "No Match Array 1": "40"

  }

]

Array 2:

[

  {

    "Parameter": "2A",

    "No Match Array 2": "80"

  }

]

I require final array as

[

  {

    "Parameter": "2A",

    "No Match Array 1": "40"

     "No Match Array 2": "80"

  }

]

For this I created following flow. Here both arrays are coming from select operation:

However I am getting following error . Pls advice where am I going wrong. 

[Paulie78]

You need to use the output of the action Root for XML as the inputs for the XML action. You have used No_match_Array_1_Table

[svivek]

Hi @Paulie78 

Thanks for above response it rectified the problem . However the final output value for one item is coming as null. Pls advice.

Following expression used:

xpath(outputs('XML'),concat('//Array[Parameter/text()="', item()?['ID'], '"]/No_Match_Array_1/text()'))?[0])

Following is the flow:

Output of No match array table 2:

 Output of No match array table 1:

Final output:

[svivek]

Hi @Paulie78 

Thanks for your solution. However I am having one additional query. Kindly help.

Your solution added size for ID: "1111", "2222" and "3333". 

However the fourth ID "4444" is NOT showing in the final result. Pls let me know if there is any way to have ID "4444" also included with size as final result as mentioned below:

Like below:

"ID": "4444",
"Object_Name": "Null"

"Size": "8"

[20Nails]

Try to duplicate the steps.

-Just add a PrepareArray1 action:
{
"root": {
"Array": @{outputs('Array1')}
}
}

-Add a XML2 action with the ouputs of the PrepareArray1 action.
xml(outputs('PrepareArray1'))

-Then add a parallel branch and a Select2 action to add the property present in Array1 that is missing in Array2 (in this case, the Object_Name property):
FROM: outputs('Array2')
MAP: addProperty(item(), 'Object_Name', xpath(outputs('XML2'), concat('//Array[ID/text()="', item()?['ID'], '"]/Object_Name/text()'))?[0])

-Then, add a compose action to union both select1 and select2
union(outputs('Select'),outputs('Select2')

This step will merge both arrays without duplicates.

Here the complete flow.

Part1

Part2

[OJBridger]

Sorry for resurrecting an old thread!

I'm having a problem in matching the IDs across the 2 Arrays I have. I've followed your guide to a T, and can't get it to work. I included the '?[0]' in the addProperty command, and it just fills every single item with 'null'

I know for a fact that the ID is present in both arrays, I can even see it on the output of each 'Select' step. The ID I am using is a date concatenated with a unique order number, so: 04/30/2023869. This unique ID is 100% definitely in both arrays and I cannot get it to match. Would the string format be causing this error, maybe the '/'? I'm at a loss!

[JAWL]

@Paulie78 , is there a way to add two properties within a single Select action?

[Paulie78]

Did you try testing the xpath query in xpather.com ?

[sree813]

Hey @JAWL, I was able to do it in my solution. Here are my two addproperty values which is converted into single expression.

addProperty(item(), 'fine_band', xpath(xml(outputs('XML')), concat('//Array[transaction_id/text()="', item()?['transaction_id'], '"]/fine_band/text()'))?[0])

addProperty(item(), 'transaction_reference', xpath(xml(outputs('XML')), concat('//Array[transaction_id/text()="', item()?['transaction_id'], '"]/transaction_reference/text()'))?[0])


Single Expression:

addProperty(addProperty(item(),'fine_band',xpath(xml(outputs('XML')), concat('//Array[transaction_id/text()="', item()?['transaction_id'], '"]/fine_band/text()'))?[0]),'transaction_reference', xpath(xml(outputs('XML')), concat('//Array[transaction_id/text()="', item()?['transaction_id'], '"]/transaction_reference/text()'))?[0])



Hope this helps you.
Thanks.