What is wrong with the following Caml query

Question

I have the following table with columns:

Editor | _UIVersionString | Title | LookupNumber | Author 
  a    |    b             | Title1|   100;800    | admin

I use the following query caml

<Or>
<Or>
<Contains>
<FieldRef Name="Editor"/>
<Value Type="Text">a</Value>
</Contains>

<Contains>
<FieldRef Name="_UIVersionString"/>
<Value Type="Text">a</Value>
</Contains>

</Or>

<Or>
<Or>
<Contains>
<FieldRef Name="Title"/>
<Value Type="Text">a</Value>
</Contains>
<Contains>
<FieldRef Name="Lookup" />
<Value Type="Lookup">a</Value>
</Contains>
</Or>

<Or>
<Contains>
<FieldRef Name="LookupNumber" />
<Value Type="Text">a</Value>
</Contains>
<Contains><FieldRef Name="Author"/>
<Value Type="Text">a</Value>
</Contains>
</Or>

</Or>
</Or>

But this always throws an error! Why???????

Answer 1

Firstly the Query is not properly created. Editor and Author are User type fields i.e Value Type='User'. Similarly, the LookupNumber in your case seems to support multiple values, hence the type should be Value Type='LookupMulti'. This is how your query should look like:

<Query>
   <Where>
      <Or>
         <Contains>
            <FieldRef Name='Editor' />
            <Value Type='User'>a</Value>
         </Contains>
         <Or>
            <Contains>
               <FieldRef Name='_UIVersionString' />
               <Value Type='Text'>a</Value>
            </Contains>
            <Or>
               <Contains>
                  <FieldRef Name='Title' />
                  <Value Type='Text'>a</Value>
               </Contains>
               <Or>
                  <Contains>
                     <FieldRef Name='LookupNumber' />
                     <Value Type='LookupMulti'>100</Value>
                  </Contains>
                  <Contains>
                     <FieldRef Name='Author' />
                     <Value Type='User'>a</Value>
                  </Contains>
               </Or>
            </Or>
         </Or>
      </Or>
   </Where>
</Query>

Finally, you should create your quires using CAML QUery Builder. It makes working with CAML quries very easy.

Answer 2

You have mentioned <FieldRef Name="Lookup" />. It should be <FieldRef Name="LookupNumber" /> looking at your columns.

Not sure whats your exact requirement but you may want to use LookupId="TRUE" and test again.

Ref: http://blogs.msdn.com/b/voyage/archive/2014/06/09/caml-queries-to-remember.aspx https://abstractspaces.wordpress.com/2008/05/05/caml-query-lookup-field-by-id-not-by-value/