title: how to add symbol in the column value in sql
body: <pre><code>SELECT 
        Topics,
        [22] as Assgn1,
        [19] as Assgn2,
        [16],
        [17],
        [18],
        case  when  [17] = 0 or [17] IS null  then [18]*100 else (isnull([18],0) - [17])/[17]*100 end  AS PercentageImprove  
  
      from
      (
         SELECT 
           fltTotalMark as [TMark], 
           intAssessmentID as [assid] ,
           vchTopic as [Topics] 
         from ManageAssessment 
         WHERE intUserID=174 
      )AS S
      pivot
      (
        SUM(TMark)
        FOR assid IN ([22], [19], [16], [17], [18])
      )AS s
  </code></pre>
  
  <p>this is my sql code to generate a table,
  here the table output:</p>
  
  <pre><code>Topics                |Assgn1   |Assgn2     |   16  |   17  |PercentageImprove|
  NULL                  |8    3|  NULL|   3   |   0   |-100
  Numbers               |NULL NULL|   2   |NULL   |   2   |200
  Numbers(Unitary Method)|    NULL|   NULL|   1   |   NULL    |0
  Occupations (people)   |    NULL|   NULL|   NULL|   1   |   -100
  </code></pre>
  
  <p>here PercentageImprove of percentage value i want show -100%,and the -100 value  show in red color and null i want to show as -,so any one help me to fix this problem..
  Thank you..</p>