Re-Deploying SharePoint List removes all the submitted ListItems

Question

I created a SharePoint List using Visual Studio 2013 and deployed it.

Later I had need to add few more columns in the List. So after adding more columns when I deployed it again then what I realized is all the SharePoint ListItems were removed automatically.

I want to know how we can deployed a SP List again without any data loss.

Answer 1

What you want to do is use the Feature Upgrade mechanism to add the columns to the already existing list.

If you just re-deploy the feature without "upgrading", then yes, the existing list will be overwritten with a new, blank list.

Here is some documentation on MSDN about Feature Upgrades.

Here is a series of blog posts by Chris O'Brien about Feature Upgrades.