Using In Operator in SharePoint 2010 Caml Query

Question

I am using the IN Operator in SharePoint 2010 CAML query to get my desired set of results, however, the filter criteria doesn't seem to work and returns all records instead of the filtered set.

Here's how my SharePoint List is laid out; the text in bracket shows the actual column name:

Department (Title)     Approver (Approver)
------------------    --------------------
Department 1            Bob
Department 2            Mike
Department 1            John
Department 3            Peter

Here's how my code looks like (EDITED, THIS WORKS!!):

string camlQuery = @"<View><Query><Where>
                    <In>
                        <FieldRef Name='Title' />
                        <Values> 
                            <Value Type='Text'>Department 1</Value>
                        </Values> 
                    </In> 
                    </Where></Query></View>";

string siteUrl = "http://mysharepointsite/sitename";

ClientContext _clientContext = new ClientContext(siteUrl);
List _oList = _clientContext.Web.Lists.GetByTitle(listName);

CamlQuery _camlQuery = new CamlQuery();
_camlQuery.ViewXml = camlQuery;

ListItemCollection listItemCollection = _oList.GetItems(_camlQuery);

_clientContext.Load(listItemCollection);

_clientContext.ExecuteQuery();

return listItemCollection;

It should ideally return Bob and John, but it returns all 4 approvers.

Is there anything I'm doing wrong? Thanks!

Answer 1

You are overwriting your string _camlQuery variable that is declared at the top, when creating the CamlQuery _camlQuery = new CamlQuery();

So you are using your undeclared camlQuery here _camlQuery.ViewXml = camlQuery;

Edit:

In SharePoint CSOM the root element for CamlQuery.ViewXml property is <View>.

So changing your query to be

string camlQuery = @"<View>
                     <Query>
                     <Where>
                    <In>
                        <FieldRef Name='Title' />
                        <Values> 
                            <Value Type='Text'>Department 1</Value>
                        </Values> 
                    </In> 
                    </Where>
                    </Query>
                    </View>";