title: Join two tables without unique records and compare two columns
body: <p>I tried to Join two tables without unique fields and compare it based on the date.</p>
  
  <p>Consider the following</p>
  
  <h3>Table A</h3>
  
  <pre><code>System ID   Start   Process
  132 1/17/2010   10/17/2010
  132 2/21/2011   2/23/2011
  132 1/16/2010   1/30/2010
  132 1/16/2006   1/16/2006
  132 1/16/2011   1/24/2010
  132 1/30/2011   1/31/2011
  132 1/30/2008   2/6/2008
  132 2/5/2007    2/8/2007
  132 2/5/2009    2/6/2009
  </code></pre>
  
  <h3>Table B</h3>
  
  <pre><code>System ID   T start T end
  132 05/01/10    4/30/2011
  132 05/01/11    4/30/2013
  </code></pre>
  
  <h3>Output Table</h3>
  
  <pre><code>System ID   Start       Process     Check
  132 1/17/2010       10/17/2010      Y
  132 2/21/2011       2/23/2011       Y
  132 1/16/2010       1/30/2010       Y
  132 1/16/2006       1/16/2006       N
  132 1/16/2011       1/24/2010       Y
  132 1/30/2011       1/31/2011       Y
  132 1/30/2008       2/6/2008        N
  132 2/5/2007        2/8/2007        N
  132 2/5/2009        2/6/2009        N
  </code></pre>
  
  <p>I am trying to consider all the records in table A and compare the Table As column “Start” with the Tables Bs “T start” and “T End”, if the Table A’s “Start” appears between Table Bs “T Start” and “ T End” then the Column “Check” in the output table will be updated as “Y”.</p>
  
  <p>I understood that the Tables can be joined only based on the unique fields ,so I tried to add an auto increment field in one of the table to avoid the duplication but the problem is both the tables consist of non-unique records and each record should be considered to identify the date. The total number of records in each table is around 60K. I am bit struck. I appreciate your kind help.</p>