Add Lookup Column to SharePoint List Programmatically

In one of my previous article I discussed how to create a SharePoint list programmatically in C#. There I didn’t discuss how we can add lookup field for our newly created list. Let’s see how, this is a sample code.

        public void createList()
        {
            // choose your site
            SPSite site = new SPSite("http://merdev-moss:5050");
            SPWeb web = site.OpenWeb();
            SPListCollection lists = web.Lists;

            // create new Generic list called "My List"
            lists.Add("My List", "My list Description", SPListTemplateType.GenericList);

            SPList newList = web.Lists["My List"];

            // create Text type new column called "My Column"
            newList.Fields.Add("My Column", SPFieldType.Text, true);

            /*create lookup type new column called "Lookup Column"
            * Here I am going to get the information from the "Title"
            * column of a list called "User Roles"
            */
            SPList targetList = web.Lists["User Roles"];

            newList.Fields.AddLookup("Lookup Column", targetList.ID, false);
            SPFieldLookup lkp = (SPFieldLookup)newList.Fields["Lookup Column"];
            lkp.LookupField = targetList.Fields["Title"].InternalName;
            lkp.Update();

            // make new column visible in default view
            SPView view = newList.DefaultView;
            view.ViewFields.Add("My Column");
            view.ViewFields.Add("Lookup Column");
            view.Update();
        }

In the above code I have created Generic list and lookup column. You can use whatever list type and field type according to your requirement. To learn more about SharePoint lists, follow "SharePoint List C# Part 1".