Update SharePoint list having lookup columns using CSOM

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint.Client;
using System.Data;
using Microsoft.SharePoint;
namespace ConsoleApplication5 {
class Program {
static void Main(string[] args) {
ClientContext context = new ClientContext("siteName");
// ListName - child List of Lookup column
List list = context.Web.Lists.GetByTitle("ListName");
ListItem item;
context.Load(list);
context.ExecuteQuery();
string strLookupValue = "LookupValue";
if (strLookupValue != "") {
try {
//LookupList - name of parent list from which we taking value
List lookuplist = context.Web.Lists.GetByTitle("LookupList");
item["LookColumnName"] = GetLookFieldIDS(context, strLookupValue, lookuplist);
} catch (Exception e) {
item["LookColumnName"] = "";
Console.WriteLine(e.Message);
Console.ReadLine();
}
} else {
item["LookColumnName"] = "";
}
item.Update();
context.ExecuteQuery();
}
public static SPFieldLookupValueCollection GetLookFieldIDS(ClientContext context, string lookupValues, List lookupSourceList) {
SPFieldLookupValueCollection lookupIds = new SPFieldLookupValueCollection();
string[] lookups = lookupValues.Split(new char[] {
','
},
StringSplitOptions.RemoveEmptyEntries);
foreach(string lookupValue in lookups) {
CamlQuery query = new CamlQuery();
query.ViewXml = string.Format("{0}", lookupValue);
ListItemCollection listItems = lookupSourceList.GetItems(query);
context.Load(lookupSourceList);
context.Load(listItems);
context.ExecuteQuery();
foreach(ListItem item in listItems) {
SPFieldLookupValue value = new SPFieldLookupValue(Convert.ToInt32(item["ID"]), item["Title"].ToString());
lookupIds.Add(value);
break;
}
}
return lookupIds;
}
}
}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Rajkiran Swain9y ago
1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Text;
5. using Microsoft.SharePoint.Client;
6. using System.Data;
7. using Microsoft.SharePoint;
8. namespace ConsoleApplication5 {
9. class Program {
10. static void Main(string[] args) {
11. ClientContext context = new ClientContext("siteName");
12. // ListName - child List of Lookup column
13. List list = context.Web.Lists.GetByTitle("ListName");
14. ListItem item;
15. context.Load(list);
16. context.ExecuteQuery();
17. string strLookupValue = "LookupValue";
18. if (strLookupValue != "") {
19. try {
20. //LookupList - name of parent list from which we taking value
21. List lookuplist = context.Web.Lists.GetByTitle("LookupList");
22. item["LookColumnName"] = GetLookFieldIDS(context, strLookupValue, lookuplist);
23. } catch (Exception e) {
24. item["LookColumnName"] = "";
25. Console.WriteLine(e.Message);
26. Console.ReadLine();
27. }
28. } else {
29. item["LookColumnName"] = "";
30. }
31. item.Update();
32. context.ExecuteQuery();
33. }
34. public static SPFieldLookupValueCollection GetLookFieldIDS(ClientContext context, string lookupValues, List lookupSourceList) {
35. SPFieldLookupValueCollection lookupIds = new SPFieldLookupValueCollection();
36. string[] lookups = lookupValues.Split(new char[] {
37. ','
38. },
39. StringSplitOptions.RemoveEmptyEntries);
40. foreach(string lookupValue in lookups) {
41. CamlQuery query = new CamlQuery();
42. query.ViewXml = string.Format("{0}", lookupValue);
43. ListItemCollection listItems = lookupSourceList.GetItems(query);
44. context.Load(lookupSourceList);
45. context.Load(listItems);
46. context.ExecuteQuery();
47. foreach(ListItem item in listItems) {
48. SPFieldLookupValue value = new SPFieldLookupValue(Convert.ToInt32(item["ID"]), item["Title"].ToString());
49. lookupIds.Add(value);
50. break;
51. }
52. }
53. return lookupIds;
54. }
55. }
56. }