title: SQL Server Return null in xml column where condition
body: <p>I have this content in my XML Sql column as you can see :</p>
  
  <pre><code>&lt;LabelRequestInputParameters xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
    &lt;Count&gt;100&lt;/Count&gt;
    &lt;ConfirmedCountByMunicipality xsi:nil="true" /&gt;
    &lt;ConfirmedCountByProvincialGovernment xsi:nil="true" /&gt;
    &lt;ConfirmedCountBySymfaExpert xsi:nil="true" /&gt;
    &lt;TypeOfLabelDelivery&gt;Post&lt;/TypeOfLabelDelivery&gt;
    &lt;TypeOfLabel&gt;Public&lt;/TypeOfLabel&gt;
    &lt;NextState&gt;Municipality&lt;/NextState&gt;
  &lt;/LabelRequestInputParameters&gt;
  </code></pre>
  
  <p>I want to select all node with count=100 </p>
  
  <pre><code>    declare @a nvarchar(max)
    set @a='100'
    select InputParameter.value(N'(/LabelRequestInputParameters/Count[@Count=(sql:variable("@a"))])[1]', 'Bigint') from Requests  
  </code></pre>
  
  <p>But when i run this query all value is null :</p>
  
  <p><a href="https://i.stack.imgur.com/K7itz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/K7itz.png" alt="enter image description here"></a></p>