Joins in SharePoint COM

private void GetParts(string searchSku)
{
  Parts.Clear();
  List partsList = clientContext.Web.Lists.GetByTitle("Parts");
  List inventoryLocationsList = 
    clientContext.Web.Lists.GetByTitle("Inventory Locations");

  CamlQuery camlQueryPartsList = new CamlQuery();
  camlQueryPartsList.ViewXml =
    @"<View>
        <Query>
          <Where>
            <BeginsWith>
              <FieldRef Name='SKU' />
              <Value Type='Text'>" + searchSku + @"</Value>
            </BeginsWith>
          </Where>
        </Query>
      </View>";

  CamlQuery camlQueryInvLocationList = new CamlQuery();
  camlQueryInvLocationList.ViewXml = 
    @"<View>
        <Query>
          <Where>
            <BeginsWith>
              <FieldRef Name='PartLookupSKU' />
              <Value Type='Lookup'>" + searchSku + @"</Value>
            </BeginsWith>
          </Where>
          <OrderBy Override='TRUE'>
            <FieldRef Name='PartLookupSKU' />
          </OrderBy>
        </Query>
        <ViewFields>
          <FieldRef Name='PartLookup' LookupId='TRUE' />
          <FieldRef Name='PartLookupSKU' />
          <FieldRef Name='PartLookupTitle' />
          <FieldRef Name='PartLookupDescription' />
          <FieldRef Name='BinNumber' />
          <FieldRef Name='Quantity' />
        </ViewFields>
        <ProjectedFields>
          <Field Name='PartLookupSKU' Type='Lookup' List='PartLookup'                    
                 ShowField='SKU' />
          <Field Name='PartLookupTitle' Type='Lookup' List='PartLookup' 
                 ShowField='Title' />
          <Field Name='PartLookupDescription' Type='Lookup' List='PartLookup' 
                 ShowField='PartsDescription' />
        </ProjectedFields>
        <Joins>
          <Join Type='LEFT' ListAlias='PartLookup'>
          <!--List Name: Parts-->
            <Eq>
              <FieldRef Name='PartLookup' RefType='ID' />
              <FieldRef List='PartLookup' Name='ID' />
            </Eq>
          </Join>
        </Joins>
      </View>";

  partListItems = partsList.GetItems(camlQueryPartsList);
  inventoryLocationListItems = 
    inventoryLocationsList.GetItems(camlQueryInvLocationList);
  
  clientContext.Load(partListItems);
  clientContext.Load(inventoryLocationListItems);
  clientContext.ExecuteQueryAsync(onQuerySucceeded, onQueryFailed);
}

http://msdn.microsoft.com/en-us/library/ff798388.aspx