[Forum FAQ] SharePoint 2013: Extracting values from a multi-value enabled lookup column and merge values to a multi-value enabled column

Question

For some business requirements, users want to extract values from a multi-value enabled lookup column
and add items to another list based on each separate value. In contrast, others want to find duplicate values in the list and merge associated values to a multi-value enabled column and then
add items to another list based on the merged value. All of these can be achieved using SharePoint Designer 2013 Workflow.
How to extract values from a multi-value enabled lookup column and add items to another list based
on each separate value using SharePoint Designer 2013.
Important actions: Loop Shape; Utility Actions
Three scenarios
Things to note
Steps to create Workflow
How to merge values to a multi-value enabled column and add item to another list based on the
merged value using SharePoint Designer 2013.
Important actions: Call HTTP Web Service; Build Dictionary
Things to note
Steps to create Workflow
How to
extract values from a multi-value enabled lookup column and
add items to another list based on each separate value using SharePoint Designer 2013.
For example, they have three lists as below. They want to
extract values from the Destinations column
in Lookup2 and add items to Lookup3 based on each country and set Title to current item: ID.
Lookup1:
Title (Single line of text)
Lookup2:
Title (Single line of text), Destinations (Lookup; Get information from: Lookup1 in Title column).\
Lookup3:
Title (Single line of text), Country (Single line of text).
Important action
1. Loop Shape: SharePoint Designer 2013 support two types of loops: loop n times and loop with condition.
Loops must also conform to the following rules:
Loops must be within a stage, and stages cannot be within a loop.
Steps may be within a loop.
Loops may have only one entry and one exit point.
2. Utility Actions: It contains many actions, such as ‘Extract Substring from Index of String’ and ‘Find substring in String’.
Three scenarios
We need to loop through the string returned from the look up column and look for commas. There are three
scenarios:
1.  No comma but string is non-empty so there is only one country.
2.  At least one comma so there is at least two or more countries to loop.
3.  In the loop we have consumed all the commas so we have found the last country. 
Things to note
There are two things to note:
1. "Find string in string (output to Variable:index)"  will return -1 if doesn't find
the searched for string.
2. In the opening statement "Set Variable: Countries to Current Item:Destinations" set the return
field as  "Lookup Values, Comma Delimited".
Steps to create Workflow
Create a custom list named Lookup1.
Create a custom list named Lookup2, add column: Destinations (Lookup; Get information from: Lookup1 in Title column).
Create a custom list named Lookup3, add column: Country (Single line of text).
Create a workflow associated to Lookup2.
Add conditions and actions:
Start the workflow automatically when an item is created.
Add item to Lookup2, then workflow will be started automatically and create multiple items to lookup3.
See the below in workflow History List:
How to merge values to a multi-value enabled column and add item to another list based on the
merged value using SharePoint Designer 2013
For example, they have three lists as below. They want to find duplicate values in the Title column in
Lookup3 and merge country column to a multi-value enabled column and then add item to lookup2 and set the Title to Current Item: Title.
Lookup1:
Title (Single line of text)
Lookup3:
Title (Single line of text), Country (Single line of text).
Lookup2:
Title (Single line of text), Test (Single line of text).
Important actions
"Call HTTP Web Service"
action: In SharePoint 2013 workflows, we can call a web service using a new action introduced in SharePoint 2013 named Call HTTP Web Service. This action
is flexible and allows you to make simple calls to a web service easily, or, if needed, you can create more complex calls using HTTP verbs as well as allowing you to add HTTP headers.
“Build Dictionary"
action:
The Dictionary variable type is a new variable type in the SharePoint 2013 Workflow.
The following are the three actions specifically designed for the Dictionary variable type: Build Dictionary, Count Items in a Dictionary and Get an Item from a Dictionary.
The "Call HTTP Web Service" workflow action would be useless without the new "Dictionary" workflow action.
Things to note
The
HTTP URI is set to https://sitename/_api/web/lists/GetByTitle('listname')/items?$orderby=Id%20desc and the HTTP method is set to “GET”. Then the list will be sort by Id in descending order.
Use Get
d/results(0)/Id form
Variable: ResponseContent (Output to
Variable: maxid) to get the Max ID.
Use Set
Variable: minid to Current List:ID to get the Min ID.
Use Copy from
Variable: destianation , starting at
1 (Output to
Variable: destianation) to remove the space.
Steps to create Workflow
Create a custom list named Lookup1.
Create a custom list named Lookup2, add column: Test (Single line of text).
Create a custom list named Lookup3, add column: Country (Single line of text).
Create a workflow associated to Lookup3.
Add a new "Build Dictionary" action
to define the http request header:
Add a Call HTTP Web Serviceaction, click on
this and paste your http request.
To associate the
RequestHeader variable, select the Call action property,
set the
RequestHeaders property to
RequestHeader:
In the Call action, click on
response and associate the response to a new
variable: ResponseContent (of type Dictionary).
After the Call action add Get item from Dictionary action to get the Max ID.
Add Set Workflow Variable action to get the Min ID.
Add Loop Shape (Loop with Condition) to get all the duplicate titles and integrate them to a string.
Create item in Lookup2.
The final Stage should look like this:
Start the workflow automatically when an item is created.
Add item to Lookup3, then workflow will be started automatically and create item to lookup2.
See the below in workflow History List:
References
SharePoint Designer 2013 - Extracting values from a multi-value enabled lookup column into a dictionary as separate items:
http://social.technet.microsoft.com/Forums/en-US/97d34468-1b53-4741-88b0-958472f8ca9a/sharepoint-designer-2013-extracting-values-from-a-multivalue-enabled-lookup-column-into-a
Workflow actions quick reference (SharePoint 2013 Workflow platform):
http://msdn.microsoft.com/en-us/library/jj164026.aspx
Understanding Dictionary actions in SharePoint Designer 2013:
http://msdn.microsoft.com/en-us/library/office/jj554504.aspx
Working with Web Services in SharePoint 2013 Workflows using SharePoint Designer 2013:
http://msdn.microsoft.com/en-us/library/office/dn567558.aspx
Calling the SharePoint 2013 Rest API from a SharePoint Designer Workflow:
http://sergeluca.wordpress.com/2013/04/09/calling-the-sharepoint-2013-rest-api-from-a-sharepoint-designer-workflow/

Answer 1

GREAT info, but it may be helpful to note that when replacing a portion of the variable "Countries" with a whitespace character, you may cause the workflow to fail in a few specific cases (certain lookup fields will not accept this and will automatically
cancel).  I only found this out when recreating your workflow on a similar, but much more complex list set.  
To resolve this issue, I used another utility action (Extract Substring from Index of List) to clear out the whitespace.  I configured it as "Copy from
Variable: Countries, starting at
1 (Output to Variable: Countries), which takes care of this issue in those few cases.
Otherwise, WOW!  AWESOME JOB!  Thanks!  :)