title: remove duplicate values from multidimensional array by single value
body: <p>Ok the thing is, Ive read and tried a lot of solutions found here based on complete duplicateness, BUT I need something a little bit different and cant figure it out...</p>
  
  <p>Because I only want to get and remove the duplicate value if only 1 of the array values is duplicate.
  And also later combine the two but that's not that difficult.</p>
  
  <pre><code>$a = array(
      array(
          'id' =&gt; 1,
          'qty' =&gt; 1
      ),
      array(
          'id' =&gt; 0,
          'qty' =&gt; 1
      ),
      array(
          'id' =&gt; 1,
          'qty' =&gt; 2
      )
  );
  </code></pre>
  
  <p>What I want the outcome to be:</p>
  
  <pre><code>$b = array(
      array(
          'id' =&gt; 1,
          'qty' =&gt; 3
      ),
      array(
          'id' =&gt; 0,
          'qty' =&gt; 1
      )
  );
  </code></pre>