title: SQL: Reading description for a columns from a different table
body: <p>I have a table (T1) with two columns (C1, C2) that describes the relationship between a parent group and child group. But this relation ship is defined based on group id. The name of the group is defined in another table (say T2).</p>
  
  <p>Eg:
  T1 has below values. C1 is for Parent Group Id and C2 is for Child Group Id. I have three groups in following order 1 - 2 - 3.</p>
  
  <pre><code>C1,C2
  1,2
  2,3
  </code></pre>
  
  <p>T2 has below values</p>
  
  <pre><code>C1,C2
  1,Parent_Group
  2,Child_Group1
  3,Child_Group2
  </code></pre>
  
  <p>Now, I need to combine above table via SQL query, so that i will get below output.</p>
  
  <pre><code>C1,C2
  Parent_Group,Child_Group1
  Child_Group1,Child_Group2
  </code></pre>
  
  <p>How can i achieve the same? </p>