I've a SharePoint 2013 form library and i do need to update a item(not the current item) in the same list, however using my logic i am able to update other fields of the particular item i need to, but couldn't update people picker fields and i am trying to set people picker field value to Employees Account ID ( which i am quite sure is the proper field to update people picker). So if possible give me some options.
While updating people picker field make sure it has employee Domain and username (Domain\Username).
In SharePoint designer 2013 have action to check whether employee is a valid SharePoint user. Before update a people picker field check this condition "If person (employee id) is valid SharePoint”. This condition will return true or false value, if the condition is satisfied then update people picker field.
Creating/Updating People picker field value using SharePoint Designer workflow is different, or we cannot directly update the field value by another people picker field value.
Suppose we have 2 lists, List 1 has a people picker column "Manager", List 2 has a people picker column "Leader", now when we create a new item in List 1 it should copy the value of "Manager" to "Leader" field in the item created in List 2, Below is the workaround for it:
1) Create a string Workflow variable "userM".
2) Assign it a value like below:
Set userM to [Current Item: Manager];#[Current Item: Manager]
Here for the first [Current Item: Manager] - Return the field as "User Id Number".
for second [Current Item: Manager] - Return the field as "Display Name".
3) Create the item in List 2.
Set "Leader" Column value to Workflow variable "userM".
Return the variable "userM" as string only
Workflow – Add users to People Picker You may wish to update a list of individuals in a SharePoint People Picker field for a number of reasons including filtering a View based on the users in this field. This is basically performed through string manipulation and in the example shown below we will update the list of viewers for a list item within a workflow step. The entire process is shown in the ref link