title: Orderby property not working properly in angular?
body: <p>I have a table consists of 3 columns like below,</p>
  
  <p>Column A || Column B|| Column C</p>
  
  <p>20    ||     Raj   ||   Driver</p>
  
  <p>50    ||    John   ||  Driver</p>
  
  <p>30    ||  Bharath ||  Driver </p>
  
  <p>40    ||    Jack    ||  Driver </p>
  
  <p>I have wriiten orderBy property to sort.
  If I sort by column A, both Column B and Column C will sort according to A(Correct).
  But if i sort by Column C, both Column A and Column B are sorting according to C... But it should not sort because column C have same values. 
  Is there any filter property to achieve this? If same value in column is present then it all the columns should not sort? Is it Possible?</p>
  
  <p>Code:</p>
  
  <pre><code>&lt;div ng-controller="ExampleController"&gt;
   &lt;pre&gt;Sort by = {{propertyName}}; reverse = {{reverse}}&lt;/pre&gt;
    &lt;hr/&gt;
    &lt;button ng-click="propertyName = null; reverse = false"&gt;Set to unsorted&lt;/button&gt;
    &lt;hr/&gt;
    &lt;table class="friends"&gt;
      &lt;tr&gt;
        &lt;th&gt;
          &lt;button ng-click="sortBy('num')"&gt;Column A&lt;/button&gt;
          &lt;span class="sortorder" ng-show="propertyName === 'num'" ng-class="{reverse: reverse}"&gt;&lt;/span&gt;
        &lt;/th&gt;
        &lt;th&gt;
          &lt;button ng-click="sortBy('name')"&gt;Column B&lt;/button&gt;
          &lt;span class="sortorder" ng-show="propertyName === 'name'" ng-class="{reverse: reverse}"&gt;&lt;/span&gt;
        &lt;/th&gt;
        &lt;th&gt;
          &lt;button ng-click="sortBy('occupation')"&gt;Column C&lt;/button&gt;
          &lt;span class="sortorder" ng-show="propertyName === 'occupation'" ng-class="{reverse: reverse}"&gt;&lt;/span&gt;
        &lt;/th&gt;
      &lt;/tr&gt;
      &lt;tr ng-repeat="friend in friends | orderBy:propertyName:reverse"&gt;
        &lt;td&gt;{{friend.num}}&lt;/td&gt;
        &lt;td&gt;{{friend.name}}&lt;/td&gt;
        &lt;td&gt;{{friend.occupation}}&lt;/td&gt;
      &lt;/tr&gt;
    &lt;/table&gt;
  &lt;/div&gt;
  </code></pre>