title: Join on multiple columns with mapping table
body: <p>I kinda need help for this one. I have customer table and mapping table. I need to join the tables. The scenario are like this: </p>
  
  <p>Table 1 (customer):</p>
  
  <pre><code>uid  job  level  status  
  1    64   68     75
  2    65   69     75
  3    66   68     76
  </code></pre>
  
  <p>Table 2 (mapping_table):</p>
  
  <pre><code>groupid  lookup_id  lookup_desc
  1               64  biker                
  1               65  stuntman                
  1               66  driver  
  2               68  low         
  2               69  high         
  3               75  individu         
  3               76  corporate         
  </code></pre>
  
  <p>Query:</p>
  
  <pre><code>select
        uid,b.lookup_desc job,
        c.lookup_desc level,
        d.lookup_desc status
  from 
        customer a
  left join mapping_table b on a.job = b.lookup_id
  left join mapping_table c on a.job = c.lookup_id
  left join mapping_table d on a.job = d.lookup_id
  </code></pre>
  
  <p>I know this query can be run. but i want make it <strong>simpler/faster</strong> or maybe u have any suggestion with my queries? or that query are the best approach (triple left join)?</p>
  
  <p>I working on Hiveql.</p>
  
  <p>Any helps will be appreciate ;)</p>