How can I create a global variable?

[porbsi]

Hi,

I want to create a global variable on a list. Every time a new item is created and a condition is met I want to increase that number by 1.

How can I create global variables and how can I update them?

I tried workflow constants, but you cannot update them.

Thanks in advance

Karin

[kapilkjoshi]

Hi Karin Hobelsberger,

There is no concept of global variable in a workflow. All variables are reset in a new instance of the workflow. You could create a column in your list of number type. When the new item is created and your condition is met, read the previous value of this variable using max(ID)-1 which will give you the value of this column 1 previous to current item. Once you have the value, increment it by 1 and save it in the column. Hope that helps.

Said that, why cant you use ID field which is auto-generated and always increments by 1 automatically.

[porbsi · Accepted solution]

Thank you. Than I will rather make a second list, where I will store those values. Like I did before, I just thought it would be great if something like a global variable would exist.

I cannot use the ID, because this is a tracking number but I have several tracking numbers for different types in the same list. So using the ID does not work.

[dan_stoll]

You could use a SQL  Table?? Not much difference than using a list though..

Or, use a Constant and update and read it using Execute SQL Action.

Update

Update {databasename}.dbo.WorkflowConstants

  Set Value="{Insert Value Here}"

   Where Title="{Constant Name}" and SiteId="{GUID}"

Read

select [Value] from {databasename}.dbo.WorkflowConstants

  Where Title="{Constant Name}" and SiteId="{GUID}"

[tomcastiglia]

Dan - I always assumed that writing to the Nintex DB tables was not supported.  Is that fully supported - to execute SQL Update commands against the WorkflowConstants table?

Karin Hobelsberger​ - do you expect that multiple users might ever update this variable at the same time?  If so, then I would definitely use a SQL table instead of a SharePoint list, as SQL will allow you to manage concurrency and prevent userA from overwriting userB.  However, you will need to create a stored procedure with lock hints and explicit SQL transactions.   Also, when you increment your counter, I assume you need the new value to be returned to the workflow, correct?

About 5 - 6 years ago, I did some presentations around InfoPath and one section of that presentation was how to implement a global counter using SQL.  I dug up the presentation including the stored procedure that I created.  I believe the code below is 100% bulletproof to ensure that if multiple users try to update the counter at the same time, they each get a unique value and concurrency is always maintained.  In this example, we had a unique counter for each form, and the SQL table had two columns: FormName (VARCHAR) and FormCounter (INT).  But you could tweak the column names as appropriate for your use case.  I have a whole slide presentation on how to implement this solution that could be easily adapted to a Nintex Workflow.  Let me know if you need more details.

-Tom Castiglia

[kapilkjoshi]

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