Server Object Model:


query.Query = "<Where><Contains><FieldRef Name="Name"/><Value Type="Text">" + "YourValue" + "/Value></Contains></Where>";




Client Object Model:

"<Query><Where><Contains><FieldRef Name="Name"/><Value Type="Text">" + "YourValue" + "/Value></Contains></Where></Query>";

<Value Type="Note"><!CDATA[<BR>]]></Value>

<Query>
   <Where>
      <Contains>
         <FieldRef Name='title_id ' />
         <Value Type='Computed'>o</Value>
      </Contains>
   </Where>
</Query>

In CAML query, 'complex' fields which store multiple values, only the 'default' value is available to query - by this I mean what would be available when SPField.GetFieldValueAsText() 

We can SPUserField as SPLookupField

<Query> 
     <Where> 
         <And> 
              <Eq> 
                  <FieldRef Name='UserField'/> 
                  <Value Type='Lookup'>" + username + "</Value> 
              </Eq> 
              <Eq> 
                   <FieldRef Name='UserField' LookupId='True' /> 
                   <Value Type='Lookup'>" + ID + "</Value> 
              </Eq>
         </And> 
     </Where> 
 </Query> 

CAML Designer

The one that works is this URL: http://camldesigner.blob.core.windows.net/offlinepackage/CamlDesigner2013.zip

The link comes from Karine Bosch's Blog. CAML Designer is the successor of CAML Builder, and from experience I can tell you this tool is much better and accurate. I've tried the both.

Edit: Looks like the CAML Designer now is a subscription application, but it is present on GitHub. https://github.com/chrisdee/Tools/tree/master/SharePoint/CamlDesigner

CAML Builder

But if you want the previous tool, the page to turn to is http://www.u2u.be/Software where you have the download at http://www.u2u.be/Downloads/U2U.SharePoint.CQB2010.zip which contains the wsp.

The CamlBuilderSetup.msi-file is located here: https://docs.google.com/file/d/0B1H-kV-5gwStUlF1OEdjWWJZNXc/edit?pli=1




U2U CAML Query Builder is now available again and updated for SharePoint 2013:

http://www.u2u.be/Software