title: MERGE 2 csv files removing duplicates using BASH or Awk
body: <p>I have 2 csv files as given below:</p>
  
  <p>Large_set.csv</p>
  
  <pre><code>0,116070742,34991221138,false,2020-02-02 15:24:30,2020-02-01 03:03:30
  0,116070741,34617138590,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  0,116070743,34603492144,false,2020-02-02 15:24:31,2020-02-02 15:24:31
  </code></pre>
  
  <p>Small_set.csv </p>
  
  <pre><code>0,116070777,34991221138,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  0,116070422,34617138999,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  </code></pre>
  
  <p>Requirement:</p>
  
  <p>I have 2 csv files of different sizes. i want to Merge the 2 csv files by matching the 3rd column (eg.34991221138 as given here) and removing duplicates from Large_set.csv.</p>
  
  <p>Expected Result:</p>
  
  <pre><code>0,116070777,34991221138,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  0,116070741,34617138590,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  0,116070743,34603492144,false,2020-02-02 15:24:31,2020-02-02 15:24:31
  0,116070422,34617138999,false,2020-02-02 15:24:30,2020-02-02 15:24:30
  </code></pre>
  
  <p>I tried using <code>cat Large_set.csv Small_set.csv &gt; new_set.csv</code> but i still cannot remove the duplicates from 1st file .
  Also have checked the solutions but my requirement is to use bash script or awk (not python or any other tool like csvmerge) due to some limitations.</p>