title: parameter to check is null or is not null in sql server 2008?
body: <p>I have one table 
    Employee</p>
  
  <pre><code>       Eno     ename   image
  
         1        aaa     a.jpg
         2        bbb     b.jpg
         3        ccc     null
         4        ddd     null
  </code></pre>
  
  <p>I pass the parameter to the query </p>
  
  <pre><code>   declare @a varchar(10)
  
     select * from employee where ?
  </code></pre>
  
  <p>? if i pass image is not null mean i want all employee details who have image other wise </p>
  
  <p>i want image is null employee details who not have image.</p>