title: How to limit a query's results to only duplicates?
body: <p>This is probably a dumb question, but it's got me stumped.  I'm basically using 3 tables to pull Campaign and Team details (below).</p>
  
  <pre><code>SELECT      GOLD.CAMPAIGN_ID,
              TEAM.ID,
              TEAM.NAME
  FROM        CAMPAIGN_ANALYTICS_GOLD GOLD
  LEFT JOIN   ENTITY ENT
  ON          ENT.CAMPAIGN_ID = GOLD.CAMPAIGN_ID
  LEFT JOIN   TEAM TEAM
  ON          TEAM.ID = ENT.TEAM_ID
  GROUP BY    GOLD.CAMPAIGN_ID,
              GOLD.CAMPAIGN_NAME,
              TEAM.ID,
              TEAM.NAME;
  </code></pre>
  
  <p>I'm able to map out what Campaigns are aligned to which Teams, but I want to filter the results only for those Campaigns which are mapped to multiple Teams.  For example, this is what some of the results look like:</p>
  
  <pre><code>CAMPAIGN_ID    ID           NAME
  830            65           Media Group APAC
  917            40           iAdvertising
  1133           9            Media Comp
  1133           2            Ad Network 5
  7163           931          Y Vector
  8149           318          Hectic Media
  8149           3827         Effective Media Net
  15982          1919         ADCMP 10
  27587          2675         MediaCorp NA
  27587          48           North Shore Ad
  </code></pre>
  
  <p>What do I need to add to my query in order to determine those Campaign IDs which are mapped to multiple teams (in this example, 1133, 8149, and 27587), or what would be the best practice in order to achieve these results?</p>