Converting an option set to a multi select option set – trials and tribulations

converting a single value option set to a multiselect option set

Multiselect options sets are one of the new features of Microsoft Dynamics 365 v9. I am now often getting requests to ‘convert’ existing options sets to the new multiselect options sets.

Strictly speaking, it is impossible to convert an old-style, single selection option set to a multi select option set. However, although not straightforward, it is possible to achieve this.

Steps to convert an option set to a multi-select option set:

Create the new multi-select option set field, which can be using either a global option set, or an option set within the field in question.
Migrate the data from the existing option set to the new multi-select option set field
Replace the original option set with the new multi-select option set field in all views that use it
Remove the original option set from everywhere that it is no longer needed

The challenge in the above is the data migration.

Previously, when I have changed the type of a field, e.g. from a text field to an option set field, I have migrated the data pretty simply, using either bulk edit or workflow. However, neither of these techniques work.

When trying to bulk edit a set of records, the multi-select option set field are not available to change. In workflow, the fields do not show to use in the update record step.

So how did I achieve the migration from the old option set to the new multiselect option set?

The technique that did work was a data update using the data import wizard.

I only had to set one value in each of the multi-select option sets – the value from the original option set. The multiselect is required for future use.

I created an Advanced Find which only included the account name and the original option set
I exported the data to a static worksheet in Excel
I changed the name of the original option set column to the new multi-select option set field
I imported this file which populated the new multi-select option set field

Another challenge that I encountered while doing the data import was that I could only import the data file from my downloads directory. If I moved the file into the client folder, Dynamics 365 told me that the file was corrupt.

Remove the original option set field

Once you have completed the migration, and it has been confirmed as correct, there is probably no advantage in keeping the original field.

As a minimum, I would make the original field non-searchable, so it does not confuse users.

If it is a custom field, and you do want to completely remove it, check the dependencies of the field. Typically, you will need to:

Delete any mappings that use it
Remove it from one or more forms
Remove it from one or more views
Delete the field

The dependencies of the original option set field will point you in the right direction to achieve this quickly.
So although there is no simple tickbox to make an option set into a multiselect option set, it is possible and it is pretty straightforward.