Updating a single field in a SharePoint List using Power Automate Flows

 

Updating a single field in a SharePoint List using Power Automate Flows

Updating a single field in a SharePoint List using Microsoft Flows (aka Microsoft Power Automate) can be a bit tricky with longer lists with lots of required fields and drop downs possibly resetting your data. The work around is code, but if there are non-developers creating flows, then this process is even more cumbersome. As a result, the Flow below will do the heavy lifting using a separate list and then anyone can populate that list from a different Flow when such a thing is needed.

First step: create the list

Here’s the input needed in this list.

List: The name of the list
SiteLink: The link to the site (trim off /lists/xyzlist)
IDFromSource: This is the internal ID of the item to update
FieldToUpdate: The name of the field you want to update. This is case sensitive.
ValueForField: What you want to set it to.

Next, create the Flow. Here’s what it will look like

 

When a SharePoint item is created or modified (the “or modified” will make it easier to correct errors along the way): Here you’ll point to the list that was created above.

Initialize Variable: If the List name contains spaces or underscores you will need to replace them. For the value, set it to an expression. Here’s the expression from the screenshot:

replace(replace(triggerOutputs()?['body/Title'], '_', '_x005f_'), ' ', '_x0020_')

This requires nesting two replace statements to first replace _ with _x005f_ and second to replace a space with _x0020_. The order is important as underscores are added so those must be replaced first. The triggerOutputs()?['body/Title'is from the dynamic content tab and that’s the code generated when the field is selected.

Next, URL Encode spaces out of the List name (yes, both are needed) with this expression which replaces spaces with %20

replace(triggerOutputs()?['body/Title'],' ', '%20')

 

The final Variable to initialize is the internal field name and that uses a double replace again

replace(triggerOutputs()?['body/FieldToUpdate'],' ', '_x0020_')

 

Now that all the variables are set, add a step to Send an HTTP request to SharePoint

The SiteLink comes directly from the list, and then the URI field is the API call to get the specific item. At runtime it will generate something like

_api/web/lists/GetByTitle('My%20List')/items(101)

Headers:

Content-Type	application/json; odata=verbose
IF-Match	*
X-HTTP-Method	MERGE
Accept	application/json; odata=verbose

 Body (variables and values to insert look like <var>):

{'__metadata':{'type':'SP.Data.<InternalListName>ListItem'},'<internalFieldName>':'<ValueForField>'}

Or written another way to be more readable:

{

'__metadata':

{

'type':'SP.Data.<InternalListName>ListItem'

},

'<internalFieldName>':'<ValueForField>'

}

Lastly, delete the item from the list that triggered the workflow. This way the trigger list should always be empty and anything that remains in the list has not executed and can be reviewed and retried.

Feel free to comment below with any questions.  :-)